Gun shop screwed up, but he did even worse. 52 years ago, when I was 10, my Dad showed me how to field strip a 1911. he put it back together and handed it to me and told me to try. I squatted down (he had put newspaper on the floor and did it under "field conditions") and started pushing on the spring-loaded button when my butt experienced a bump, followed by my front end hitting the floor. I was a bit upset and asked what was going on with the kick - he told me I didn't check it to see if it was loaded. I mentioned I had just watched him working with it and he told me it didn't matter - until I verified it was empty and safe, it was loaded and dangerous.
52 years later and I have never made that mistake again - any cop (or other gun handler) who isn't just as careful has no business handling weapons.