I had sort of the opposite experience a few years ago. I was doing a morning ride one Friday in preparation for a Sunday century to Brooklyn. Mr. Flintstone pulled onto the trail a ways in front of me. I kept my pace and started to catch him. When I got somewhat close, I slowed down because I didn't want to draft. The fact that I caught up to him must have triggered 'roid rage because Fred lifted the pace. I stayed with him but kept my distance. He was not happy and lifted the pace even more, trying drop me. I stayed with him, still keeping my distance until I finally turned off the trail to climb a hill and head back home.

You can read all about it here:

Fred Tried to Shake Me on the MUP