If you went shopping first and then to the water, how could they even know you aren’t still shopping — unless they are keeping track and following thousands of shoppers after they park, following them into the stores and following them to the water — all the while keeping track of which shopper own which one of the hundreds of cars parked in the lot?
And if they towed, you could prove it was their error by producing the shopping receipt (and denying leaving the mall area.)