I've known about the "grip sensitivity" syndrome; it really exists. One of Jeff Cooper's own instructors had it. Everyone at Gunsight could shoot the sample CombatMaster just fine, but once it got into this one instructor's hands, it would malfunction. It wouldn't malfunction for anyone else. Apparently Cooper coined the term "grip sensitive" on the spot, and even included a description of it in the article he wrote for Guns & Ammo magazine; back in the 70's somewhere.
I've heard tell that the head gunsmith back in the Seattle company used to go nuts trying to solve the problem. Sometimes he had no choice but to replace the CombatMaster with a ServiceMaster or a ScoreMaster. The larger guns don't have "grip sensitive" effects; but of course, are not as concealable. It sounds cool that there's at least a concealable "almost CombatMaster" sized version that can work for "grip sensitive" customers.
It also sounds like Detonics USA is serious about customer service! Congrats on your "QuarterMaster".
...Deeton