Try seeing it from his point of view.
He normally see's cyclists hugging the gutter. Assumes that's where they should be. Now some guy is in the middle of the road - either he must be doing it to wind me up, or maybe he doesn't know I'm there. I'll just beep to let him know I'm behind - again probably not realising cyclists can usually hear what's behind them.
He doesn't appreciate that cyclists like being where they need to be early, so they don't have to worry about the hazard they're avoiding - and trying to merge with a stream of traffic at the last second.
A more friendly toned conversation would have been more beneficial, now he's probably gone home moaning about the cyclist who was in the middle of the road shouting abuse at him (all he probably heard was a f*** you as you cycled past). I can't say I'm perfect, and I certainly get annoyed when I get beeped at and unfortunately respond with hand-gestures and swearing more than I should. But it's something I'm trying to work towards.