Also, keep in mind that in this state, they'd be hard-pressed to prove theft if there was an unpaid for item in the bag - if they didn't see you select it and conceal it, they have no case. For example, if the clerk forgot to ring an item up but bagged it anyway... it's happened...
The most they could legally do would be to take the item back, and maybe if they are feeling especially froggy they could give you a trespass notice that would get you arrested if you ever came back...