Shouldn't the instructor in this scenario try to avoid a deadstick landing? In the Netflix drama &quot;The Crown&quot; (season 1, episode 4) Prince Philip has flight lessons with Group Captain Townsend (below is an image of that scene, I was unable to identify the plane).

After Prince Philip complains about the noise of the engine, Group Captain Townsend deliberately turns it off, and they both enjoy the silence for a while. After some chat, Prince Philip notices the ground getting closer:

Prince Philip: &quot;Shouldn't we get her started now? The ground seems terribly close.&quot;
Group Captain Townsend: &quot;No, it's too low to restart, sir. We'll do a dead-stick landing.&quot;

And they land safely.
My question is: if that was a real event, shouldn't Group Captain Townsend (as the instructor) interrupt the relaxing gliding with a warning? Something along the lines of &quot;excuse me, sir, we're losing altitude, if you want me to restart the engine we have to do it now&quot;, or even &quot;I'm restarting the engine now&quot;. I mean, shouldn't he be checking the limit altitude for restarting the engine?
I'll not ask why Group Captain Townsend didn't do that, it would be off topic, opinion-based and, despite the Group Captain being a real person, that scene is fictional anyway (The Crown is not 100% historically accurate). I'm just curious about the most probable behaviour of a real instructor in a situation like that.
if that was a real event, shouldn't Captain Townsend (as the instructor) interrupt the relaxing gliding with a warning? Something along the lines of &quot;excuse me, sir, we're losing altitude, if you want me to restart the engine we have to do it now&quot;, or even &quot;I'm restarting the engine now&quot;. I mean, shouldn't he be checking the limit altitude for restarting the engine?

This question appears to be predicated on the idea that the instructor had no plans to land the plane with the engine turned off. Having watched the scene, I'm far less convinced that this is the case. In fact, it's not until Philip remarks that the ground is coming up that the Captain tells him they'll be landing deadstick.
In the series, this instructor featured is a renowned flying ace with huge amounts of combat flying experience including a number of forced landings and ditchings.
Bob Hoover (who you could argue with cut from a similar cloth) regularly displayed and demonstrated with the engines turned off, up to and including landing in that configuration.* On the basis that turning the engine off was deliberate and not an emergency, I don't think the scene after that point is particularly unrealistic. They appear to be making a straight in approach and land on an airfield - it's entirely plausible the Captain made a deliberate decision to land with no engine from the very start.
*Example: