James Sleeman writes:

B) An engine stall (failure) is very likely to result in a forced
landing, but not necessarily a crash.

An aerodynamic stall is unlikely to cause either, unless one is already very
close to the ground.

C) An aerodynamic stall is benign if you expect it, if on the other
hand it happens while you are in a high angle of attach mode of flight
due to attempting a far too hasty and high G 180 out of a boxed canyon
which you have suddenly found yourself in the wrong end of (as the
article posted implies), is quite likely to result in a spin at low
alititude followed by a very distinct crash.

In such a location, an engine failure is likely to cause the same thing.

Going by the very brief article, it seems much more likely that this
is a case of aerodynamic stall than engine failure as was reported.

There isn't enough information in the article to assume either way, and the
passenger said it was the engine. Why are the passenger's words being
unconditionally dismissed in the absence of any other evidence?