I'll second a vote for hammer follow.

You might be able to verify it with an empty pistol. Make sure it's unloaded and lock the slide back with no magazine. Push the slide stop down and let the slide slam forward. You might have to do it a few times. If you do it and the hammer goes down when the slide slams shut then you have issues.

Oh, and this isn't really good on the gun. A few times probably won't hurt but I wouldn't do it too much.