Speedy likes to give a few coughs when he very first starts trotting. I indulge him. We walk for a bit, but then I drop the reins to the buckle and let him trot a circle or two where he clears his lungs. We do it every single day.
In the midst of our on-the-buckle-throat-clearing trot out, the arena sprinkler popped up with a very loud PSSST!!! You can imagine what happened.
Speedy's bolt, refusal, and continued bolt took maybe 5 seconds. It happened so quickly that when JL looked up, we were already flying by her working the pulley rein. When we laughed about it later, I told her how I was refusing to get tossed off. She said she wasn't worrying about me coming off. Instead, she was concentrating on my pulley-halt technique. Always the trainer!