The night following the explosion, my colleague on Principal horn gave me the inside scoop on the gun's "premature emission" last Tuesday night. His girlfriend works in the Wardrobe Department, so he hears about virtually everything which happens in the company.
Apparently, the actor who plays the Marksman got some of the gunpowder in his eye and had to go to the Emergency Room at a nearby hospital. His eye was flushed out successfully and he's all right, thank goodness.
He insists that he did NOT pull the trigger prematurely; that it was a "pyro issue" with a overly-hot mixture of powder. This is what I figured had happened.
It is interesting to note that although the actor is supposedly "okay" now, he has NOT made a return appearance as the Marksman for the remaining shows this week!