Does she have a legal leg to stand on if she never left the store and had every intention of paying for it?

I ordered a sandwich at the grill, ate half and then went back to work at her register. She left the other half of the sandwich at the grill. When she was done with her shift, she would pay for it and get the other half but security stopped her and had her charged with retail theft. She never left the store and left the sandwich at the grill with the employee who makes the sandwiches (that girl still has her job). Is this right?