To be constructive.....Are you wearing a proper gun belt? The belt over the gun on the MTac is an important part of the good gun retention. Some of that depends where you wear your belt, body shape, etc. A belt keeps my pants on..
A good belt keeps my gun from sagging on my strong side like Matt Dillon.I normally set the scew tension where I like it for draw/reholster, but I cinch up a little tighter on my belt when carrying IWB. It appears to me that the leather on the holster's inside conforming to your body furnishes a certain amount of extra compression retention due to the contour of you body (depends where it is, I guess some folks have more defined curves than other :)).
Thanks for sharing your accident information.