Thanks folks, and keep 'em coming.
I'll certainly be more careful in future, but it helps to know what to do in case that doesn't work. As for students getting depressed or demoralised, this one certainly didn't. He'd been bought the TL as a 30th birthday present, and at first just wanted to overfly his house. But by the time we got back he'd decided he absolutely HAD to learn to fly helicopters, and was working out how he could afford to do the course. So maybe I got something right.
