1-just because he killed someone next to you shouldn't make you shoot him unless he didn't Id which he did.
2-you can't prove he saw who killed him since he might not have been paying attention.
3-you can't presume there was another t based of gunshots, for all you know it could've been another inno
4- again unless you followed him the entire round, which you didn't since you were in a gunfight with another player, even if he did just enter the room he could've t baited earlier in the round
5-you said he was shooting at another player so you can't kill him for shooting near you, it's not t baiting as he was in a gunfight
6- since you can't prove he never had a reason you can't say it would've been RDM if he was inno
Over all I wouldn't have even warned you for it since it was in the heat of the moment and broken wasn't going to either, you ruined it by getting mad and disrespecting the people involved