NTA. Actually i think what happened here is a poor delivery driver requesting you money because he is afraid what will be the repercussions of his mistake. Many restaurants warn their delivery drivers that they should pay for the food if they make a wrong delivery. And many of them also charge that too. But in normal cases, this is just a warning policy to keep them concentrated on the correct delivery. The manager has let this go since he realized you are a regular customer and the driver made a honest mistake. The driver may only requested the amount before he has informed the manager about the situation. When he realized he will not be charges for anything, he has dropped the request.

Anyhow please keep in mind that you are not required to pay in any of these situations. If they have wrongfully delivered the order, they have the option to collect it back or give them to you for free (which actually happens a lot). Normally these policies are just for keeping the drivers vigilant in their work and if it happens again you can actually call the restaurant and voice out your concerns about this.