My guess is, since the rush had begun, it would mean having to get three warm bodies back in line with one coupon each. An instant hassle because three people would have to go to the end of the line and wait.

Unjust and Intolerable under any circumstances, afterall, two warm bodies at a table and one warm body with three coupons presented after the order was placed entitled you to get three coupons redeemed on one order, you know, to save time.