Holstering Safety Question

One of the reasons I've always carried DA/SA pistols is that I can put my thumb on the hammer as I guide the pistol back into it's holster. This is very reassuring to me & striker fired guns worry me in this respect. I've never had an accident, or known anyone who has. But, the fact remains that there is a real risk that a shirt tail, a cuff button of a jacket, even a finger could get into that trigger guard and ruin your day. I know that once it's in there & safe it should only need to come out during an emergency. But, I believe that you should train with what you carry & we regularly run dot torture drills which require a lot of re-holstering.

My question is, if your thumb is flat on the back of a Creed, would an accidental trigger pull allow the pistol to discharge? It's kinda hard to tell from dry firing it. the hammer does move forward but it looks like only about a third of the normal travel. Maybe this is not enough inertia to send the pin into the primer? is there an internal safety that come into play here when the hammer isn't allowed to travel fully rearward?

The only safe way I can think to test this would be to place a piece of tape across the back of the slide to simulate your thumb on top of the hammer. Then try to fire the gun down range.

Any thoughts on this?