I've helped a food bank guy load donated food from the Safeway. It is not substandard. Bananas, for instance, are donated if they have any spots. Bread is donated after a day, when it's perfectly edible. Also a lot of milk.
Second Harvest is a good place to research, and they oversee my food bank. Strict food safety rules are enforced, and they donated a refrigerated van to us.
SH is huge, though. The big gorilla of Bay Area food banks.
One thing they were able to do is freeze their precooked egg patties that would have been thrown away for texture reasons for later use in a protein stock for a charitable kitchen's cafeteria in some way that I was not informed of.
This corporation was a prepared food retailer, not a grocery store in case I have been too unclear. In their case they used nitrogen-packed presliced tomato pans to streamline food prep for their line, which is why I chose tomatos as the example.
If an otherwise reputable food retailer begins serving a secondary market with what is definitionally substandard products, it opens a large and murky doorway to liabilities extending far beyond a mere lawsuit. What if the next kitchen mishandles the food and serves gross food to people in need? Even hungry poor people will dislike week old, vinegary tomato slices."
"the food service industry" : that term doesn't seem limited to prepared food retailers, if that's what you meant.
as for "week old, vinegary tomato slices" : Second Harvest, at least, would outright reject those.
It would have to go straight onto a table somewhere, since the shelf life would be almost zero.