Jack wrote:
However, as we are well aware, an operating engine is not necessary to
continue controlled flight. So the question remains: why was it
necessary to use the parachute? Was the terrain unlandable, or was the
pilot more conscious of the parachute's capabilities than the aircraft's?

He was also trailing an unknown quantity of rope that was doing unknown
and possibly unpleasant things to his airframe, plus unknown damage from
the collision itself.

And of course, while we do unpowered landings routinely, it's truly an
unexpected and unwelcome emergency for a power pilot. After experiencing
the shock of a mid-air he was faced with a choice of going ahead with an
unfamiliar procedure or hitting the parachute, and I can't blame him for
going with the devil he knew.

--
Michael Ash
Rogue Amoeba Software