His account was most likely from the Brazilian-Portuguese community server's that were merged. He simply has not changed his nickname/Account data for the EU servers we all currently share. He should contact Technical Support for further assistance to change the nickname/transfer necessary data.

This is from my own experience with Matchmaking ever since it's official release, we don't have accurate stats provided on how exactly it works, but from what I have experienced when teams go unbalanced like this is either because of players leaving the battle, and different times of the day plays a part as well, for example starting at 17:00 UTC the matchmaking system is pretty fast, players with closer ranks to each other put together (maybe one-two occurrences during the day) 23:30 UTC things begin to slow down and then that's when I notice some teams going unbalanced, either their ranks are a bit to low, they don't have strong enough equipment to keep playing and they leave, then other times nobody joins the match at all (however, I do rarely experience this) the match goes on for the next 3-4 minutes that feel like forever with half of your team not there possibly because the matchmaking system cannot find anybody to rank you with those players in your current match. These are of course, in my ranks, so I am not sure if it's different for the lower ranks, it could be. Also, again this is my own experience, not actual stats.

So to sum it up. Players leave the match for whatever reason (equipment, connection issues, loading errors), different times of the day play a part and when the hours are not so active, the battles begin to become more unbalanced because matchmaking can't find players that match your team and opponents strength.

I have lately been facing issues with the Flash version myself and clearing cache, uninstalling, restarting my PC, router etc...No progress at all, Flash is being slowly less and less supported, as well as less worked on as mentioned in some of the v-logs. However, like the other answers here, give the HTML5 version a try, I'd also recommend trying the Mobile version if possible, hopefully it resolves the issue for you.

Entering the game (Try the Flash Browser version and see if that changes anything).

Hey there mate, very unfortunate to hear that. We do not publicly discuss chat bans or warns, so for your case please PM our Chat Administrator @Defender or @Hate to discuss whether it was a justified ban or not. 

As for the "Report Section", the EN Locale no longer accepts Chat violation reports based off of players screenshots, click here to read about the Chat Violation Section closure for more information as to why we made this change.