Stick to your report, it's your best friend. Have a copy ready to refer to. Refer to it wherever possible. "As I said in my report..." Emphasise the captain's actions - taken out of context his words are quite mild, but put into context of running however far he ran to shout them right into your face, completely different.
Now, I've been in a situation not entirely dissimilar to yours. Just remember what the hearing's for - to determine whether or not the captain abused you after you gave the penalty try in the 78th minute. The club may well come armed with ten witnesses who'll all swear blind that you're the worst referee they've ever seen and the first 77 minutes were absolutely ridiculous and so on and so forth droning on and on while the panel falls asleep. The panel doesn't care about any that. At best, those are mitigating factors. They have nothing to do with the event in question. All the panel wants to know is this: did the captain abuse you after you gave the penalty try in the 78th minute?
So there are two likely actual defences to the charge, neither of them particularly convincing.
1. "Yes, he went to talk to the referee, but the referee completely over-reacted." If they start saying this, take the phone away from your mouth and breathe a big sigh of relief. They've now admitted that 95% of your report is accurate, and it doesn't matter that there's ten of them contradicting you on the last 5%. They all have a very compelling motive to be lying about the last 5%. You don't.
2. "No, he didn't say anything to the referee at all." A bolder move. If they have video that backs up their story, they win, you're a naughty boy for fooling people on the internet. They won't, though. They think that because there's ten of them and one of you, that makes their account more believable, so if everyone tells the same consistent lie, it wins. Doesn't work that way! From the panel's perspective, of course they're all going to cook up a story to get their captain off the hook. They see a lot of teams trying to do that. It's a far more likely explanation than a referee in good standing suddenly deciding "I'm going to screw you lot over and then send your captain off". Bottom line, it's still your word against theirs and the panel needs a very good reason to take theirs.
Keep it simple, stick to your report, emphasise the captain running over and shouting in your face.
(The one time when it's acceptable to worry is when half the witnesses they bring out are from the other club; that starts to negate the previously-overpowering "well, you would say that, wouldn't you?" position that the panel starts from. Happily, I find that the clubs most likely to be in this situation are also the clubs that nobody else likes enough to go to bat for at a disciplinary.)