Reporting players outside post game screen should be possible

We've all been there. way too many times we wait in cue, get to champion select, start chatting, get the champion or position we wanted and then... several minutes into the process... some jerk starts going nuts in chat for whatever reason and somebody dodges. sometimes its because you decline a trade in ARAM. sometimes it a controlling douche in a rage because you wont play the champion they demand you play or dont like your summoner spells. Some people cold open with calling people racial slurs. one time I got into a game and was immediately told I was Jewish, then challenged to denounce Jews and when I refused and called him out for racism.... you guessed it, someone dodged to get out of the lobby and escape 30 minutes trapped on a team with a raging anti-Semitic troll.
the end result is that we all have games where someone is being awful and ruining a game for someone else, but you cant report them because they or someone else dodge to get away. Sometimes I've even dodged myself simply so I wouldn't need to spend an entire game being harassed by a crazed troll, and then you get punished with a wait timer or slowed cueing. I think we should be able to report someone by looking up their name after the fact, and if you file a fake report then your account should be banned for a bit. It can slow joining games to a crawl and really make you want to do something else instead. It seems like there has to be a solution to this problem...