Awful story. It's a damned shame for anyone to buy it like that--whether it involved cycling or not (that it does, and the way the stories lean in their portrayal of it has to be especially compelling to a group of cycle commuters, of course).
Apparently we can't/won't know what the argument was about that led to the man's death. I think that this particuar group here, though, can easily see the strong possibility that it involved something to do with what one or both of the vehicle operators were doing as they moved down the road. The considerations for not confronting drivers unnecessariily are strengthened in light of it, though (at least they are for me).
Along the routes I currently ride most often, I do not feel the need for carrying (and if I did I wouldn't worry about the legality of it). If I ever do feel the need to carry, I certainly will. I only hope that I don't suddenly feel the need to carry at a time when I'm not carrying.
Ya pays yer money, ya takes yer chances...