At a small, busy roundabout coming out of town this morning. I was taking the first exit. Looking to my right car one was indicating right, car two (a Ford Ranger type thing) behind it indicating left. As soon as car one started turning right, giving me the space to manoeuvre I pulled out, only to be beeped at loudly by car two who had decided to go straight ahead instead. He then (was a man driving) tailgated me for around a quarter of a mile before doubling back on another mini roundabout.
Was I the unreasonable one to have started moving when I did? Should I have waited to make sure that car two was definitely going left?