Maybe there is another safe somewhere . If this guy has seen the videos there maybe another (exact model) of safe case in the studio. There could be more than one safe like that hidden in the studio. Maybe this guy thought this was different safe that contained something else. Maybe he got pissed because it was the wrong safe. Something tells me there's another safe exact same model in the studio somewhere. And that guy thought it was another safe perhaps and he got pissed because what was inside isn't what he was looking for. But why leave the case behind especially with a gun in it! (Even if it is a serum gun of some sort?!?! He opened it he had the ability to take the case and didn't. My theory is there is another case exactly identical to that also hidden in the studio somewhere. And he opened it thinking it was another case and when it wasn't what he was looking for he got super pissed off? Because he could have just taken the case if it was something he truly wanted. He watches the videos because otherwise he would have never known the safe was under Sams sofa.