This doesn't seem like a "terrible" TSA experience at all? I know everyone loves to hate the TSA/Government, but this seems like a relatively normal procedure, especially for a 16 year old traveling with a 19 year old.

According to his description of events, the first TSA officer did nothing wrong but check his note and then send him through to make sure everything checked out. I know the OP might be insulted (because he's 16, he doesn't need a note), but that doesn't mean it's a terrible TSA experience when someone asks.

I'm all for hating the TSA, but I would not call this terribly by any stretch of the word, it's about as far from terrible as one could get.