Aquila is correct.
There is no requirement to contact the owner of a bag before cutting the lock. Attempting contact is often done at small airports but virtually never at larger ones. There are signs and warnings all over the airports about using TSA locks or your other locks might be cut. In that respect, as long as they didn't open the gun container, which SHOULD NOT have a TSA lock, they followed the rules.
Not that it's an excuse but I'd assume the "gift" is a result of having to cut the lock. Typical disgruntled, powerless employee trying to feel powerful.