Dr. Liz, that is scary.Hope hope hope that never happens to me. I have given up starting the greenie TB's though.
Interesting question for the horsie types. I'm still in my ancient cages on my ancient GT, but I'm going to have to pay attention to how I start and stop, even with the old school easy cages. When I run my labs with my bike I definitely keep my left foot free since I may need to put it down if they do something unexpected. They stay on my left the same as without bike. Curbs or a rock on trails usually get a right foot out. Sigh, some day when I actually have a new bike . . . I'll graduate from the cages.
Since I've been having right seat bone issues in my dressage work (always have to watch or I'll sit too much on the right) I've been purposefully doing downhills with my left foot in front and lots of things with my left on my bike. I'm hoping it will help even me out more.