I mount and unclip from the left, too. Several years ago, wearing new shoes and clips I found I couldn't unclip my left foot no matter what I did, so I thought, good thing I've got plenty time to stop, I'll just unclip with my right and put that foot down first. Clipping out- easy beans- slowing,stopping- put foot down - stumble and down I go.
Thankfully that has only happened once.
On my trainer I'll mount and clip in on the right but still not confident enough to try it on the road.