I have been working with leather all my life, and most of my life dealing with liars. Now he may have actually convinced himself that the holster pulled the trigger, but IMO he is a liar. I have heard a lot of people say "I didn't do it" for various reasons.
Leather does not easily crease, we use tools and moisture to crease it. I have a tool for cutting leather to form creases. I use bones and steels to form leather creases where they will show. Leather does not have an inclination to pull into a trigger guard if it is not pushed in. And even worse he claims it is worn leather which unless the weapon had a hair trigger it would have move out of the way, but then it would have moved out of the way of the substantial trigger guard of the Glock. Even furniture grade leather does not crease in that fashion. Galco used heavy veg tanned leather, that leather got that way because he intentionally worked to fit his lie. You can tell by the leather wrinkles(stressing), which would have pulled the leather away from the trigger. Besides the fact that the Glock trigger is nothing like a 1911 trigger, it has travel before it is fully depressed and cannot fire until it is fully depressed. And the photo shows clearly the gun is fully inserted, by the form marks on the holster matching the gun, that it is not depressed. The only way this leather got to the position in the photo, is because the person responsible pushed that leather in. Which indicates to me he knows it is a lie.
You can believe what you want, but I go by what I see, and the evidence is clear that he is lying. You can disregard that if you wish and continue to believe the nasty leather holster pulled the trigger, but I don't and I won't. It is as simple as that. BTW is there any evidence that Galco paid a settlement? Or accepted responsibility? Did he even file a suit against the nasty leather company?
A lot of depts had trouble with this holster
http://i46.photobucket.com/albums/f104/1954mike/DSCF0195.jpg
It is the Jaypee scabbard holster, as can be seen it has a fully covered trigger guard and reinforced. Yet police officers still had ND with the holster, through no fault to the holster, but a common practice that has taken years to train out. Holstering with the trigger finger in the trigger guard. It is one of the reasons that many police dept including the US Air Force went to this holster.
http://www.gunblast.com/images/WBell_PoliceHolsterHist/Police-Holster-History-115.jpg
IMO he holstered with his finger in the trigger guard, and fired the weapon without realizing what he did. But then to make matters worse he went on a campaign to convince himself and others it was the nasty holsters fault.