And to add to Kalin above. Coming from a leader standpoint. I think that's something important to remember, a lot of the time people start groups because they want to play with their friends and have a good time and want to organise fun stuff to do with something they all enjoy doing and make friends too. They're not doing it as something especially serious or professional. Though of course, each FC is different, because some are just there for serious content progression and no-BS. But I think for many, it can be about having fun with people.
If somebody screws with that, your position as a leader might be "they screwed up, we deal with it appropriately" but what happens when somebody, let's say somebody who contributes a lot found they're just really uncomfortable with them? Because of their attitude/behaviour and it sucks the fun out of doing stuff with them? You have to make a decision on it.
As a leader do you:
a) take the line: "I already dealt with it. This is the end of it. No more action required."?
b) kick the offender?
c) try to work things out?
Option a) could ultimately leave to the non-offender leaving, if the offender was genuinely an a-hole, do you really want to make the choice between somebody who is being an a-hole to somebody who actively makes positive contributions?
Option b) will seem unfair and may ultimately be so, but you're there to have fun, they were the a-hole and if people are going to be a-holes, they must also be prepared to accept the consequences for it. They're not entitled to being there. It's something you voluntarily run for fun, you're not an organisation, you're not a business and you may not necessarily owe them anything.
Option c) would ask more from you than is your duty, but I think for many people is the instinct if caught in the middle. This is what I normally do, and there is still risk of the outcomes of option a and of option b and even both of them at the same time. I have encountered each and it's not fun when things get worse not better as a result. But if it works out, then things get sorted and all is hunky dory
I think as a leader, you kinda gotten play it by ear a bit. But inevitably, you'll make bad judgment calls.