Probably related to the chap who shouted pretty much the same at me as he passed me on teh left as I turned right off a country road into a smaller country road on Saturday. He may have been commenting on my lack of indication, but when I started the move (going slightly uphill, so not all that fast) he wasn't in sight - I looked back, obviously, to check it was clear. And as I turn, I like to have both hands on the bars.
I made an exception though, and took my left hand off the bars to make a gesture at him as he went past. I chose the 'Agincourt' model...