The bullet doesn't just stop at the carrier tho, it ricochets into the floor or ceiling.It was a big event and I'm betting OP got there when it was hectic and they missed having him sign off
If they didn't get his sign off they shouldn't have made him pay. From OP's description, there was no damage beyond marred paint. If that is all the case then Safe Fire is garnering a lot of bad press over a nickel's worth of paint.
I think you should know there are consequences for damaging the facilities, even if it's just a scratch.