Right vs Wrong

Consider this scenario:
Suresh walks into a super-market to purchase some things. He stands in the queue for billing/payment. The cashier incharge of the queue is clumsy and takes a long time to serve each customer. Further to accentuate the irritation, he starts serving customers out of the line. This pushes Suresh across the limit and he shouts at the cashier. The guy aplogizes, but continues to be very slow with his work. Finally, it is the turn of Suresh. In hurry to finish fast, the cashier only bills for certain items which Suresh purchased. Suresh realizes this, but doesn't ask the cashier to bill for the missed items. He cooly walks out of the shop paying only half the money of what he purchased.

Now, was Suresh right or wrong in deciding not to correct the cashier? Clearly, the cashier was not upto his job and he was wrong at serving customers who weren't in the queue. Will Suresh's decision be a good payback for his mistake?