I'd argue that they were trash as soon as the package was open.

I'd question the store owner and ask if he regularly sells open bags of chips, then question the person who actually stole them and see if he knew the chip eater.

Then we'd all go home, but probably not my client, cause if you're the type to eat floor chips outside of your house, you probably don't have a great job, and were fired when you went to jail and didn't show up, which probably caused you to be behind in rent, and subsequently evicted.