I think Smith and Wesson will make it right.
I purchased a used semi auto rifle (another manufacturer), took it to my Dept's range and it went full auto (in front of a dozen other officers) on my first time out. The next day, I was back at the LGS and explaining my "problem". I told them I could send it back myself, but I wanted them to do it so I had a rock solid paper trail because I needed to "CYA". The LGS sent it back and it was made right.
I hated to have to do it, but, I'm too pretty for jail