This is actually a great point, ozz, and thanks for mentioning it.
For guys who are considering doing hip escape from mount you have to adjust it. The reason that I say this is because if you do the normal shrimp with both arms on one side, it will result in getting your back taken, or a gift wrap to arm triangle. Instead use more of a foot drag.
So lets say you are on bottom and goingfor there right foot, you'll lean on your left side bring your right over there right ankle then push there knee with your left hand as you move your hips back.
Personally, I try and slip the leg out underneath their leg instead of working my hips out, to set up half-guard. Usually it isn't much harder (though I have pretty good flexibility and am relatively small).
Then I use the traditional hip escape form to free my other leg and create space.