A few things here.
1) I feel for these guys family and friends. They're the real victims here because they lost loved ones in a way that is completely avoidable with some common sense and thought.
2) There is no longer, in this day and age, for anyone to continue to call drinking and driving a mistake and giving people an out, or excuse, for stupid behavior. There is no way, at all, that people their age do not know the dangers of such stupid actions and I do not feel on bit sorry for someone who kills themselves in a drunk driving accident. You drank, you drove, you did it to yourself.
Thankfully, in this particular case, the two drunk people didn't kill someone else who wasn't drinking and driving but heading home from work, or from a trip, and got killed cause two people decided to be completely reckless idiots and risk not only their own lives (which were lost for no reason other than stupidity) but the lives of anyone else who might have been out.
3) What Roger said wasn't wrong, or off, at any level other than he shouldn't have done it right away simply because of the fact that emotions would be running so high at that time. He's right though. Where were the rest of their friends? When it became clear these two are too stupid to think for themselves why didn't someone else step in? Sometimes you simply can't let people make the decisions for themselves, cause they think they're Gods and nothing can touch them, so you've got to make the decisions for them.
Roger should have waited, to say anything immediately afterwards is insensitive. However his message is clear, and correct, and the response from Bam is actually more laughable to me.
We know you're sad. And we all understand that. But sad, hurt, and insensitive as the timing was your anger toward Roger, for simply pointing out the truth, makes you look foolish.
I'd be much more angry at my friend(s) for being so foolish and making such a stupid, and frankly there is absolutely no other way you can describe it that is anymore fitting, decision. They're the ones that robbed you of their smiles, their jokes, their lives, and caused you to be crying all day, not Roger.