No one has any right to decide who is and isn't a coward based on their suicide. Perhaps you underestimate just how hard it is to actually kill yourself. It's not an easy option. Have you ever been scared of anything? Have you ever run from a gang, or a dog? Would you hesitate to go skydiving, or bungy jumping? Ok, so now think that if you ever do that, you pretty much know that you're going to be fine, in the end. Think what it feels like to stand on an overpass, and jump off, and know that you're not going to be fine. What kind of a state do you have to be in to do that?
What do you want to say? "He killed himself, he was so selfish, because he made me feel bad"? That's not hippocracy at all. Do they make you feel so bad that you actually try to kill yourself?
People don't commit suicide because something bad happens. It's about how they feel at any one time, and if someone actually commits suicide, then you can take it for granted that they weren't in a stable mental state. I'm sure he didn't weigh it up in his mind and logically decide, "Yes, suicide is certainly the best option in this circumstance". So, with this case as an example, he almost certainly didn't commit suicide because he had a fight with his girlfriend: that might of been a trigger, or pushed him over the edge, but the decider is whether your state of mind rocks onto that edge or not. If you get to that place, then it seems right to do it. If you don't experience that, then you don't kill yourself, (not for reasons like this, anyway). Also, it seems sensible to consider the idea that he had a fight with his girlfriend because he'd become unbalenced, not the other way round.
In the end, no one can understand what it's like to be in someone else's position, especially not someone suicidal. You might have had much worse happen to you, but it's how you feel that makes the difference, and often that's got no relation to what your like's like.
One last thought: It's much rarer for a boy to commit suicide, (it's a statistic, don't hit me), and it almost always means that they are in a really, really bad way. I'm not saying that is without doubt the case here, but it's quite unlikely that he just had bad day.