I have found that the bolt needs to be part of the preflight inspection. Just wiggle the aft tip of the pant and if it moves, tighten the bolt. I hesitate to really tighten it as it would crush the pant material, so it's a judgement call. If you don't tighten it enough it for sure will come loose. I'm guessing, but it seems like about 10 ft-lbs is enough. One way to fix it would be to put a small (SS?) metal plate on the surface screwed to the pant, maybe with one screw behind the hole. Then put a star washer under the bolt head. Those bolt heads bug me - they must be costing 2 knots! I was going to either build a cavity in the pant to make them flush or to find a button head bolt. I did neither.

Gary