Correct me if I'm wrong because I haven't seen a training syllabus in years, but are students shown how to restart an engine in flight or is it deemed unnecessary risk? I know it made an impression on me when my instructor did two things in flight; pulled the mixture and then restarted a windmilling prop, and; took the effort to stop the prop completely near the stall, bunt, get it windmilling and started again. From memory, it took about 1200ft, but my memory is hazy on that subject. Besides being great fun, it was a good learning experience, but I can imagine CASA's reaction these days. I can understand in some way, a pilot who has never been shown otherwise, seeing a windmilling prop and thinking/hoping it still has some power.
If anyone sticks around in GA long enough, they'll eventually run a tank dry and lose power. Lucky the guy didn't have a full load of pax.