When I was training I had a rough running engine on departure from our local airport. Having around ten hours dual at that point I didn't really know enough to be very 'concerned'.
The instructor took over for a minute or two, checking things over, then handed back control to me. We flew a wide circuit (the pattern being over a largish city), with enough height to
be able to land clear. On final we were 500 feet above circuit height: the advice being that we would have enough height to glide in if the engine gave up.
As we rolled out on final we were surprised to see how many fire trucks and ambulances were waiting for us. Apparently the local plan didn't consider the size of the aircraft in trouble,
and just scrambled the lot. A normal landing ensued with no major problems.
What impressed me then, and still does now, is how my instructor assessed the situation and then let me get on with it. I've no doubt that if I'd started to panic he'd have taken over.
Instead it ended up as a huge confidence booster to a newish student. So, if you're reading this Geoff, thanks mate!
For me, having read all your comments above, I think that unless you've been there and done it just congratulate the pilot for what they did. There but for fortune etc.