Good to hear the son is OK, too often the accidental shootings end with bad results.
It pays to check every time you handle a gun to see if it is loaded, makes no difference if you just watched someone else check, check for yourself too. At a recent gun show an individual picked a gun up from a table, brought it up to his shoulder, aimed at a light fixture and fired. The gun went off, the light fixture was damaged, and both the dealer and buyer had red faces. The gun had been on the table for well over eight hours, numerous people had handled it, many of them picking it up and pointing it in the direction of other people.
The point is, this dealer, did not check, the "looker" did not check, this was a serious accident waiting to happen. BY the way, the dealer now double checks, and puts a wire tie throiugh the action where his guns can not be fired.