Different people have different cardio.
And, there are many things you have to take into account.
Maybe they were sick and they are just recovering.
Maybe they don't sleep well.
Maybe they don't eat well.
Maybe they have a crooked nose and can't breathe properly.
Maybe they don't know how to breathe at all.
Maybe they carry too much muscle around.
I don't have anything against the guys who gas during rolling.
I only dislike the guys who arrive late to class on purpose, so they can skip all the work-out, and then gas and put that up as an excuse for getting pwnd in the mat.
When people are drop dead tired they tend to react slower, so it's a lot easier for him to get hurt, and a lot easier for them to hurt you (like they will just crank your arm because all they want to do is "finish" that roll, no matter what).
Not to mention someone can, in FACT, pass out due to exhaustion.
So instead moaning about the guys with poor cardio, help them out.