I don't mean to sound dismissive, but these things do happen. My two primary rules about cycling in traffic are 1. Predict others, and 2. Be Predictable.

Drivers won't see you. Or they'll misjudge your speed or distance. They'll be inconsiderate.

I don't necessarily agree with cycling as if you're invisible. We should TRY to be as visible as possible, which means taking an entire lane on occasion where it helps drivers see us. But of course, you can't assume they see you when in cycle.stig's situation. The most common type of car/bike collisions where the car driver is at fault are the left and the right hooks. cycle.stig's situation is a bit different but similar.

I try to let these things roll off my back. I don't always succeed. The sooner I forget it, the better off I am. Sometimes someone does something like this and I can forget about it in a minute. Those are the lucky times.

Confronting the drivers rarely helps things. I'd say in this case, it wasn't a bad thing and the driver might be more conscious. But we'll probably never know.