The main problem with that issue is, first that the spec would happen most likely after the death, and second that there are some guys who'd kind of abuse that, like if they are the ones who start fighting and when somebody fights back they report him. Which is why imo it should first be a main chat warn for people (mainly the reported guy but as a reminder for all) not to fight during a race (unless it's IV of course) and then if we see the player starting again some punishment. It goes a little bit the same as for ram and block... when somebody reports a rammer it's obviously after getting rammed, so we have to see it happen again clearly on purpose (the "on purpose" part is not necessary for fighting as I don't know of any unintentional fighting lol).
As for lobby and ended race I think it should be more tolerated, sometimes maybe just ask/do sth because it can still be annoying, but there's no race being wasted or anything.