AITA for letting my nephew miss a flight after he forgot his passport?

I drove my nineteen-year-old nephew to the airport for his first international trip. Before leaving, I asked whether he had his passport. He tapped his backpack and said yes.

At check-in, he discovered he had packed an expired passport. The valid one was at home, forty minutes away. With traffic, I might have retrieved it and returned just before the bag-drop deadline.

I refused to try. I had already taken the morning off work and believed he needed to experience the consequence of not checking.

He paid $420 to move his flight to the next day. My sister says I turned a teachable mistake into an expensive lesson because I was irritated by his confidence. She would have driven back, but she was two hours away.

I say a rescue attempt could have failed and cost me more work time. The truth is that uncertainty was not my only reason. When he tapped the backpack without looking, I felt dismissed, and at the airport I wanted that gesture to have weight.

He now checks every document twice. He also no longer asks me for rides.