Fired!

So my husband works 12 hours shifts as a cook at a hospital. His job let's them have 3 free meals a day. My husband skipped his meal and grabbed potatoe chips and a Gatorade for lunch and left home for his lunch break. Theu fired him the next day for "stealing the chips" is this legal? Everyone in his job takes chips, pop, snacks and they don't get in trouble. What can he do about this? *edit* They are allowed to take home their food if they leave.