I can't see how you can get your finger into the trigger guard unless you crook it. The Serpa doesn't make you do that.
The Serpa for the 1911 makes me do it. Let me try to explain it a little better.
My index finger isn't real straight. It's bent toward my middle finger enough that the rest of my finger is resting on the holster. So I have to bend my finger, like a hook, and push the button with my fingertip only. So my problem with this holster (and it's MY problem not the holster's) is that my finger is bent, pushing pressure toward frame when the gun comes out. I'm just a slip away from getting the finger into the trigger guard.
Again, not an issue with the Serpas I have for my Glocks or my Sig. Those holsters are a little flatter and the button is a little wider. I index my finger along the slide/frame the way I always do and the holster releases, just like it's supposed to.