The transaction is fundamentally between a human client and a corporation. With an AI shopkeeper or with a human, it doesn't matter - you don't steal from the till attendants, you steal from the corporation.
There's a scam where two people go into a store and pretend not to know each other. One gets change from the other, but doesn't have the correct change. They then get the cashier involved to help with the "problem" by making change from the register till. But, via a fast-past set of confusing operations, trick the cashier into giving incorrect change. It's still considered stealing if you intentionally trick the cashier into giving you incorrect change.
An AI cashier does the same and all of a sudden it’s the fault of the human and is liable for prosecution. You should know better than to steal.
Businesses looking to replace people with this can’t have it both ways.