a punishment to fit the "crime?" (child behavior)

Learning to lose with grace AT HOME is also a wonderful place to start.  Had he been able to lose gracefully in the family he wouldn't have had a public melt down.  Being allowed to compete in the pulic is the reward for learning to lose gracefully in the family/private.

Disagree vehemently with the second paragraph. What happens if a friend confides in him about being abused or the son is abused by someone else (teacher, etc)? You, as his parent, as the one person he should trust, just told him he won't be taken seriously. I understand crying wolf, but that's why you make damn sure he understands the severity of saying it and never to claim it falsely again.

This flagged to me. Dh could of handled it better. I would of clearer laid out the unacceptable attitude (listing it clearly), explained it was no fun, maybe given a chance to change and if no change we would be gone. Back in the car. At 10 he could kick off by himself. But it would b shortlived with no audience. Threats are pointless if not carried out. DH let it escalate. And they both got angry and the suitation went pear shaped.
I would have a chat about his behaviour. But it sounds like bad sportsmanship his been an ongoing thing and it will take alot of effort on both sides to change. what does he think about losing and winning? What does he think good sportmanship is? I would play more games in the house and praise him and reward for positive attitude. And deal with the negative then and there.
As for the child abuse cries. I would explain what that is and why it is destructive and wrong and how we should help friends and ways we could.
Talk about how he felt about the spanking threat, and why his dad thought it was a valid option.
But all in all, the mini golf incident was a whoops a daisy on both sides. I think you need to look at the bigger picture of what your plan is to deal with the behaviour long term and how you plan to parent him when he has an attitude melt down.

Does he have similar meltdowns often, just that this one was bigger than usual? My son is gluten intolerant. We have him on a gluten free diet to control tics, but if he eats gluten now he will often have an emotional meltdown. He's almost 13 and will seriously throw a toddler tantrum if he accidentally eats gluten. It's like he gets possessed by a gluten demon

Just wanted to add that perspective. For the crime and punishment dilemma, I think I would separate the two main issues - competitiveness and his rude behavior towards his father.

Have you considered making family board game night a weekly tradition? That way you can practice winning and losing in a controlled environment. You could share your expectations for behavior with him before every game and even add a reward system.

I also like the idea of practising winning and losing using a board game or card game
IMO ( I have a lot of opinions today..!), as an adult ,manipulating the game to allow kids to win or lose allows you to teach them how to behave appropriately for each outcome
Unless they are 15 going on 35 like my younger DS and too smart for their own good and then you will have to resort to the old saying..." Age and treachery will always overcome youth and skill"...aka cheat!Ha!

I haven't read all of the responses but I'm wondering if the meltdown was exacerbated because he was possibly tired, hungry, dehydrated, etc. from having played in the tournament. It's certainly no excuse for the underlying problem of being a poor sport but I know that whenever one or more of those factors comes into play with me or my kids, things can devolve pretty quickly into a meltdown.

I've never been a big fan of punishing a child by taking away a sport (particularly a team sport) for a behavior that occurred outside of that team/sport. Particularly a team sport-there is an implied commitment to the team and pulling one person from the team feels to me like punishing everyone on the team for the child's behavior. 

One thing I saw is that dad is the coach? I noticed over the years of two kids playing soccer that when a kid's dad coached the team, often the kid felt like they had to perform at a higher level to 'make dad proud' and disappointment was greater when the kid felt like they had let him down. (And this was true for my own kids as well.) Maybe it is time that dad steps aside and your son plays for a different coach-different coaching styles lead to different behaviors and different lessons about sportsmanship. And your son is 10-as far as sportsmanship is concerned, he is still heavily into the learning curve. This is the time where you find your mantra and stick with it- mine was always 'there will always be someone who plays better and someone who plays worse, your job is to have fun, play your best and be a good sport win, lose or tie.' 

As for the yelling of abuse thing, I am not sure what I would have done.

I'd like to look at this from a different angle rather than suggesting punishments: what examples and expectations of excellent sportsmanship and respect for others has he been shown? Maybe a summer research project on JJ Watt or another athlete known both for excellence and sportsmanship would be in order. (It may dawn on him as well that JJ Watt treats his parents with enormous respect.) What is the culture of sportsmanship on his team? His dad, as coach, has enormous power to influence not only your son but all the boys on the team. What are the expectations around congratulating other athletes on a game well played (whether win or lose)? What expectations exist for behavior off the field? These things should be discussed at practice. Perhaps the team could also work together on some community service projects.

One thing I was really impressed with at the school I taught at this year was the way the sports coaches expected discipline, respect and sportsmanship from the players on and off the field. We teachers had to sign forms weekly for each athlete to show whether they had been completing their work, treating us and others with respect, and generally representing the school at the highest level. If not, they weren't allowed to play. It made a huge difference in the way many of the kids acted inside of school.

Unfortunately, there are tons of examples of bad sportsmanship and poor behavior in college and professional sports, and kids grow up confused about how real men act. I have respect for coaches who bench or remove players who are not representing the team well both on and off the field, and even more respect for those who demonstrate and communicate behavior expectations in these situations. I'm paraphrasing here, but if you were ever a fan of Friday Night Lights, Coach Taylor liked to say that he wasn't just coaching football players, he was building men. That included demonstrating and guiding appropriate behavior, and assigning consequences for poor behavior when needed. But the demonstrating and guiding was always the first priority.

As for the "child abuse" thing, I would talk to him and ask if he thought through the potential consequences of what he said there. Probably he didn't, and simply wished to stop the punishment. Ask him - was what you said truthful? And if not, what kind of person do you want to be? Do you want to be someone whose word is respected and believed, or someone who is known as a liar? Kids are impulsive and needed to be guided to think through their choices. He's at a very pivotal age for developing character and behavior, and your husband is in a unique position as both dad and coach to shape the man he will become. I would encourage him to think less toward punishment (including threatening spankings) and more toward how he can positively influence and shape your son's behavior going forward.

Just my two cents.

I think a long day in the sun, being tired etc can make anyone not act like themselves.  Combine that with dad being the coach and feeling the need to step up you game for dad probably makes for a stressed out kiddo.  I like the idea of addressing the abuse thing though.  That's definitely something that needs to be explained to him in a calm manner like you intend to do.  

For a punishment that fits the crime, imo, that would be losing out on doing competitive activities with the family (since he appears to be able to stay in control during sports). That would mean no games with sis, no mini golf with dad, no racing to the car or anything of that sort.

If he thinks that he has it so bad that he's abused he's not only have to examine what real abuse is like but he'd lose a lot of "perks". You only have to provide him with a place to sleep, clothes, food and education. Anything beyond that could be removed. Toys, rides to a friends house, special treats, outings, electronics. He thinks his life is so bad now, he has no idea. I realize it's not the same as being physically abused but clearly you're not going to beat him to prove a point.

Just to add a another perspective...

In many countries, mine as well, spanking IS considered child abuse. I believe there are better ways of diciplining a child, but flame away ladies

ETA: I still think you should have a long talk with your son about how serious child abuse is, and that those accusations should never be thrown out like that. 

I don't see how not letting him play soccer fits the crime. The "crime" wasn't at the soccer game-it was playing miniature golf. 

He needs a real good discussion about children who are abused and how serious that  comment was that he made. But you also said this has happened in the past--not the comment but the the behavior. Nip it now or you're going to have a real issue. I still think he needs to write a letter of apology to where he played putt putt. I am sure people saw him....he needs to own his behavior.

If I could go back and live my life again, knowing what I know now, and have someone threaten me with spanking at the age of 10, I would yell child abuse too, because it is. I would defend myself the second time around.

What defenses does a 10-year-old have against a full grown man threatening to strike him on the butt several times and the kid's a couple of years away from being a teenager? Just stop and think of that mental picture for a moment.

I don't know anyone who engages in this type of behavior. It's outdated, and we as society should have moved on from striking children as "discipline." I don't even know how it's legal that you can't hit adults, but you can hit children.

I think your husband should reexamine his parenting skills. Telling your kid you're going to smack them on the rear at age 10, which is coming up on teen years, is childish and immature and just bad parenting in my book.