You get alot of silly stuff on commutes. Mostly, with other roadies, we end up working together, and having a chat. As I'm on fixed, and if we are both going for it, conversation is quite difficult sustaining a high RPM, whilst the other guy is sat there in a big gear.
You just have to let it go, you will get guys chasing you if you pass them, just because, then they do silly stuff in traffic and are gone. I sometimes get passed by a guy whose none too keen when I pass him. I can't have a conversation with him as he has headphones on, I've tried and failed. The guy only ever passes me on the flat, or downhills. Show him a slight incline and I'm much quicker.