If you have a prone model who survives an armor save, but cannot improve their cover, can they use the third bullet under guts roll and spin on the spot? The hang up is hat they're already prone. Relevant rule from Guts Roll: If the two previous options are not possible, the Trooper must go Prone, facing in any direction its player chooses.
I always played it that if it is prone, it can still "go prone facing any direction the player chooses". Ruling otherwise (ie. i shoot you from behind, if you pass your armor save you are stuck because you are already prone) feels like being a jerk.
Reading the rules explains the rules (in this case at least) :) Yes, you can spin around when gutsing prone 3. If the two previous options are not possible, the Trooper must go Prone, facing in any direction its player chooses.