need some feedback asap on an issue with DH

So DH's BM was his friend from college. Over the past year or so, they have really drifted apart. I think they had drifted long before that but in the last year it's become crystal clear that that is the case. DH has really only realized/admitted this in the past few weeks though. Essentially, the friend wants to be friends with DH more than DH wants to be friends with him and DH wants to sever the friendship.

They got into a huge argument over some stuff two weeks ago, that really clarified that the friend does not understand DH's current life. Background- the friend works at a college as a res life person and is constantly IM'ing DH at work. He doesn't seem to understand that DH can't drop whatever he's doing to chit chat, despite the numerous times DH has told him that. So, two weeks ago, DH got super angry after the friend got snippy in an IM convo. The friend didn't understand why DH didnt' answer something immediately; mind you DH had gotten up when his boss needed something so he wasn't at his computer. When he got back and saw the comment from the friend, DH, incensed, proceeded made a comment about having a 'real job' to which the friend shot back something about being on call 24/7 and dealing with drunk college kids and sexual assaults and that DH doesn't know what having a 'real job' is. Awesome, right? Apples and oranges. DH got fed up and has led to the past two weeks of them not speaking.

To complicate matters, DH is supposed to be the friend's BM in his November wedding. Further almost all of the friend's other friends have fallen away over similar issues over the past few years, which has made planning for bridal party and bach party very difficult. None of the friend's friends are responding to DH's emails, and the friend is getting anxious (as well he should, it's his bach party, but it can't be helped).

DH now feels that the friendship is beyond repair (he doesn't really want to repair it, either) and feels that it would be better to drop out now and NOT be the BM in the friend's wedding rather than sticking it out, be the BM and then let the friendship fade. He feels that in dropping now it would leave a less bitter taste than if he were to go through with it and then have the friend look back and say 'yeah that a*& was our BM and he screwed us.' He thinks that in dropping now, the friend has time to find someone that would care enough to do the duties as BM and not someone who was just going through the motions; the friend has a cousin who is close, that DH thinks could do it very well.

DH is so torn over this and I sort of am too. If it were me, I think I'd just stick it out and get it over with and then let the friendship fade as gently as possible, but I can see DH's point.

So, I'm looking for your thoughts and advice. DH drafted an email to send to the friend today telling him he was dropping but I got him to hold off on sending it for a bit.

Thanks ladies.