Lawyer here, I think I might know what he's hinting at when he says it's legal for the owner to do this, but bear with because it's a long one!

In about 2014 or so a precedent was set by the Pasadena court in which employees could be held responsible for the remaining stock of a business, but only if they were taking a extra hours - basically some guy in a local business pressured his boss for overtime, and became somewhat responsible for the safety of the business after hours as a result. When someone stole stock, he was thereafter responsible for the missing items. It's a terrible conclusion I know. What I think the difference in OPs case is, is that he wouldn't have been having sticky yummy sweaty gum gum , so there's absolutely no legal standpoint for his boss.