"Jim Macklin" wrote in message

Automatic deployment of spoilers and thrust reversers
depends on compression of the main gear struts and probably
also the nose wheel strut.

I've never flown the 737, but have the 727 and 747. Boeing used to be
pretty consistent in running systems through the models. On both the 727
and 747, main gear compression *and* main wheel spin-up are both necessary
for operation of certain ground systems like reverse thrust, autospoilers,
autobraking, etc. IIRC, on the 727, nose gear compression is also required
for autospoiler deployment. Without a trip to the basement for research, I
can't recall the details. I *could* believe that after a landing in several
inches of snow, certain main wheels may not have spun up enough to release
the reverse actuators.