If you can't take the time to glance at the killfeed to see red or green after you kill someone because of "combat pace" you are probably not even capable of finding your way out of the spawn. It's an easy, basic skill in any FPS that is not unique to RO2 in any manner.
If you are dumb enough to shoot first, ask later on a consistent basis, you deserve what you get. Unintuitive? Is it too much to ask for people to ID what they shoot first? Even ignoring the ways to tell friend from foe, simple map common sense and basic logic will do MORE THAN FINE. If it shoots at you, kill it. If it doesn't, check to see what it is before killing it, because it's probably a friend.
I thought rule 1 was don't shoot friendlies. I mean, in any game with FF it's a pretty obvious rule of "don't shoot your friends".
It's an error in judgement and a lack of thought. It happens. What happens afterwards says more than TKing. A "sry" goes a long way. It isn't the game's fault people can't figure out someone isn't shooting back at them or not saying sorry.
Fortunately, the ones who don't want to actually learn are gone now, leaving the ones who at least give it a whirl.