What the first few posters said...Happens to me still to this day, and mine has been through hell and back with me. 4,000+ rounds. However!
I did have one Magazine out of my 5 that didn't lock back. I called SIG to tell them so and buy one..had my wallet out, she asked for my name, address, serial number..and said "Alright, It's on the way to you...should be there in about a week"
Swear, all I said was one of my magazines wasn't locking the slide back like it should.
Back to the slide release though. Happens to this day. One of my main guns but shoot so many of them on a regular basis that even though it's my most fired and my big hands don't help either mind you...I still nip that slide release here and there, mainly during drills and such.
This sucker has been on watch with me
trust my life to it.