...if you are an overloaded single engine pilot doing an NDB/DME approach...
I think some of you have missed the point here. Re-read that word that comes before single engine. Yes,OVERLOADED. Once a crew is overloaded, whether it be single engine,single pilot GA or multi engine, multi crew commercial then all bets are off. There's no predicting what can happen, as all the assumptions about what you'd normally expect the crew to do are out of the window.
The trouble is, unless the crew tell anyone, or there are big enough clues for ATC to spot then nobody knows and there's nothing anybody can do to help them.
Is it totally inconceivable for a very inexperienced pilot to turn up at a busy airfield expecting an ILS approach because he hadn't briefed properly and then finding its an NDB? Struggling to fly the approach procedure, selecting the wrong frequency for tower? Being so fixated on landing that he didn't even see an aircraft lined up?
Yes there are many opportunities for a pilot to exit the above scenario, but that's the beauty of target fixation...you just don't see anything other than what you're focused on.