Feeling a bit guilty for posting without at least trying a fresh battery like the technician recommended, I just went out to try it. I don't want my own credibility to be low for sounding close minded. I fought the button for about 15 seconds to get it to turn on...
The gun still would not fire on a new energizer. No shots. After getting the gun back inside and removing the battery, about 45 seconds later, I heard the blow off valve hiss. Okay, maybe I'm getting CO2 into the marker and not knowing it.
I tried it again, keeping the CO2 bottle and the gun vertical to ensure no CO2 liquid was getting in. The CO2 charged the gun as normal, but it still didn't fire a shot. Usually, if CO2 gets into the marker it is after at least a few shots and normally the gun is pointing down. That is what the video on the Smart Parts web site shows too.
Removing the bottle and battery caused the blow off to hiss a second time about 45 seconds later.
I will report this to the tech department before sending it back to them, but the gun is simply not working.