Im assuming hes talking about the british military. And generally speaking our military stretchers are meant to be used quickly to get someone out of the hot zone and towards medical personel. Even if it is a spinal injury its better to get them out than to leave them in a firefight waiting for a spineboard.
Generally immobalizing spine injuries arent that common in the military (in recent conflicts) generally your moving someone immobalized by an IED blast so more than likely part of a leg is missing.
I would rather have a good lightweight manufactured stretcher of just relying on my skills of finding things to make a makeshift stretcher.
X2 Any type of emergency move, ( note* emergency for a medic/firefighter not the same as civilian). Exactly, hot zone, (active shooter,chemical, ), building on fire, or crumbling, avalanche zone, forest fire, car on fire, etc Where the risk to life is greater then the risk of spinal injury.
there is actually a huge push right now, my agency included. Where we don't use or transport people on backboards anymore. May use to pull them out of a car we just cut the side out of, or to move a pt up a steep embankment. recent studies have shown prolonged time on backboards make injuries worse, or create a problem where one was not before. C collars still used a lot and recommended. But someone can have a c colar one and at least lay on a padded gournay with less harmful effect, and still be protected.