You care for the same reason that I care: regardless of the veracity of this story, it presents a really interesting law thinking exercise.

Your last point is what I am having trouble with. If I am to argue a "reasonable expectation" perspective, it is inappropriate and unfair that I would not also offer the same protections to the girl. She has a reasonable expectation that food in a fridge is safe to eat, regardless of her previous actions. Proving malicious intent becomes simple in that case.

BUT...what about this hypothetical situation:

*I walk to the park from my house. I cut through my neighbor's property (which is illegal) to get to the park because I have done this for 20 years and he has never said anything about it.

*On the next day, I once again trespass his property and walk to the park. Unbeknownst to me, however, my neighbor has decided to throw broken glass all over his backyard. It's his private property, and he there is no municipal statute that disallows throwing broken glass all over your own property.

*I cut my feet to shreds and get Tetanus as a result.

Who is at fault? My neighbor is under no obligation to tell me that he did that, even though he may have full knowledge that I trespass every single day. Why does he have to accommodate me, when I am the one who is breaking the law?

Similarly, the girl in the scenario broke the law by eating the man's food. It's not going to send her to prison, but it is theft, which is illegal. The man has no obligation to tell her anything. It's not her food - if she steals it, she steals it. I cannot fathom the man being in any trouble at all.

Now, regarding OP's scenario: unfortunately, he has done WAY too much to provide real evidence that he was trying to maliciously harm her, so my argument and analogy is largely academic. Had he not said anything, I see no fault in him at all.