My Fenix light has a lockout function too. I have to hold down 2 buttons together to lock and unlock the power. Also, the head swivels back so the buttons are partly covered by a metal ridge. So far it has always worked well to prevent battery drain.
Thanks for sharing your story. It's a good reminder of safety and how quick accidents can happen. I'm glad you were able to get to the hospital and are on the road to healing now. Best wishes for a full recovery.