I believe my recent experience as indicated at the title is of general interest to this community.
My recent BN Patek 5146P with a deployant is letting go the strap when my hand rubs against surfaces while the deployant still remains snapped on. This happened twice over the past month and the watch slid from my wrist to the floor. Fortunately, in both cases there was carpeting so my watch got only minor beating. Actually the first time the deployant scratched the back of the watch. The strap is not padded, thus the deployant is always snapped tight. What I found out is that the "pin" that supposed to grab on to the strap is not really doing its job. After wearing the watch for a short while, the hole in the leather becomes slightly wider, and does not grab the "pin" tight enough, so when there is a slight movement of the tip of the deployant (i.e. tang part) away from the wrist caused by rubbing against an uneven surface (e.g. folds of a shirt) the strap is let go - then the watch gently slips out of your wrist while the deployant remains closed. After these repeated events, I am worried that this may happen on a solid surface or on boat or a ship with disastrous consequences. Therefore, I began to seriously consider giving up my depoyant and start using a regular tang.
Appreciate hearing comments on my experience.