It's a theft thing. Middle managers are concerned about employees purposely making accidents so that they may then eat. It's all about that money honey
I work for a pizza place and routinely take home orders that didn't get picked up, maybe fancier restaurants just throw their stuff out. We also give those orders to people experiencing homelessnness if they stop in around closing time.
They have that policy, but most shift managers aren't assholes and don't care. Also, I know a lot of places around where I live donate the excess food to shelters.
Who do you think throws it out? It's not the manager, but probably one of the regular employees. They can just as easily "throw" it in their car instead...