Tell me about it! I field stripped and cleaned it on arrival, watching a youtube video. Mine's actually the later, easier one to do- I don't even have to fiddle with the spring. Did this several times to get comfortable with it.

My son and I shot at the range, and he also shoots the CZ 75 I have gifted him... so I was taking the PHP down to show him, preparing to clean it (he REALLY liked this as a shooter). He sat next to me, as I was going through the steps. I had the slide off and was working on wiggling the barrel out, while he watched... and was examining the frame.

He said, "here, you left this", and placed the takedown lever on the mat we were using!
Luckily the detent didn't come out, and I was able to use a small allen wrench as a punch to press it back down and slip the lever back into place.
But not before I said something to the effect of "what.. oh God stop it... " he now knows not to do that again!