This is true for every pilot isn't it? You are responsible for your own flight in the first place. If you can help out others, time permitting, then you can. But your own flight is still your primary (and only) responsability.
What if you, in a multimillon dollar jet, are taxiing behind another multimillion dollar jet. After a few minutes you hear the pilots reporting gear problems... the gear won't retract.
Eventually they get back to the airport. After landing the pilots notice the gear didn't retract because someone forgot to remove a pin... your fault because you didn't report something "red" that's not supposed to be there (you were taxiing behind him)? Your fault because you didn't see that?