I look at it like motor vehicles. He's responsible for everything in front of him. If he can't stop in a pinch he's out of control. The way you describe it, it's not like you darted out of the woods like a deer at 90 deg., which actually does happen here. I'll allow him having been mildly annoyed to slow down, but any incident would have been be totally on him. By mildly annoyed I mean grin and bear it, or a simple 'hey that was close' and move on down the path. Anyone that rides on a MUP and expects not to come across dogs, straying children, slow riders, generally distracted pedestrians, and the aforementioned deer is delusional to start. And frankly, I don't have issue with anything in that list myself. The way MUPs are laid out here I perceive them more as shared public park spaces for relaxation, than roadways or Olympic training venues. If I want to go fast I take my chances in the street.