So I was walking out to my tool shed the other night when I was attacked by a cottonmouth.
I had my G17 with 10 rounds in the magazine. I emptied the gun, and when the slide locked back, the light fell off the gun, and looked like this:
You'll notice that the screw was broken clean off of the rail. And no, it was not overtightened. I had just put it on the gun, with a penny to tighten it.
After what happened, I will never buy inferior lights again.