I pulled my foot out a few weeks ago, on my fixed using toe clips and straps. Coming back from the club run climbing hard up one of the hills on the Fosse Way and managed to pull my foot right out, huge wobble, almost hit the crown jewels on the cross bar but managed to stay on it, just. I normally set the straps a just touch loose, so I can get my feet out without messing with them, but so I can still pull up on them, on this occasion I must have tried to pull up with the toe pointing down instead of up.