I recently had to emergency stop when approaching a junction where I intended to turn right. The reason being that a gentleman approaching the same junction from my left decided to cut the corner, meaning that we were in a head-on situation. He stopped, and I realized he had approached his turn quite slowly. He got out and asked me to reverse back to allow him to carry on with his manouevre, and his explanation was that he had a broken arm and couldn't turn the wheel fast enough to take his correct route on the turn, but that he was quite fit to drive as his car was an automatic and it was his left arm that was broken!