If somebody gets killed with some of those guns he left laying around, I hope it comes back to haunt him. If they busted into his safe and took them, I'd be totally on his side. But he doesn't have a safe, and I'm not on his side.
Why stop there? Why not blame him for having an insufficient safe?
What if they stole the safe?
"He should've bolted it to the ground!"
Boof.
The only safe he should require is his own abode.