This player was abusing the votekick system with no particular reason.

SteamID:
https://steamcommunity.com/profiles/76561198027883261

Evidence:
https://imgur.com/a/MxC0pp1

Thanks for the report, Catbug. We'll keep an eye for this and take appropriate actions.

Just to say, that firepot, catapult and (I think) balista damage doesn't count as team damage. Some trolls exploit this to attack teammates and pretend to be innocent. Plus, there are other valid reasons to initiate a vote-kick. In any case they should provide the reason when it's not obvious.

I'm not saying this is what has happened here. I'm just saying that for me the evidence in inconclusive.

Fair enough, I've uploaded the only part I recorded of one of the matches, might take a while to show decent quality:

https://youtu.be/TuqOiYsRBMM

How would I go about reporting such players, record a large portion of the match? Recording and uploading a match for context to report votekick abuse seems a bit cumbersome if I'm being honest.

Also note that I am on one of my alt accounts since I occasionally have to jump onto low ranks to remove smurfs.

you are really RPing the shit outta your alt acc

Ah, so I didn't realize he was targeting you. I thought you're just reporting him.

The video gives a better picture of what's going on: the classic tale of noob trying to vote kick a smurf. I will warn him next time I see him.

Vote-kick spam is annoying. And when they don't provide a good reason, the whole server gets annoyed by this. So you can ask them to stop (as you did) and after their second or third attempt you can vote-kick them back. Don't forget to explain why in the chat, or people will get mad at you as well. I can't promise it would work but it might be worth trying.