I doubt the police department is an expert in static electricity. I am not an expert either, but I think it is unlikely that static discharge would cause a primer to discharge. There is maybe a slightly higher chance it caused a powder charge to ignite. It would seem the chance of it setting off three rounds simultaneously is close to nil.The police departments official finding was an electrical discharge caused 3 bullets to discharge at the same time hence launching the revolver off the shelf. The man had a single electrical burn on his index finger. Aparently the new carpet caused the ststic buildup the gun sitting on a metal shelf was ok but the shelf was sitting on a rubber mat causing an isolation.
As related, I have a hard time believing a static discharge causing an AD in a cartridge arm,period, let alone a revolver. To get a 'spark ignition' you have to have dissimilar electrical potentials.
That being said, I am calling BS on static electricity causing a AD in a cartridge revolver. Cartridges are, for all practical purposes, sealed metal canisters. Unless the clearance between bullet and case wall were too wide so as to leave a gap, there would be no path for the static discharge to get to the propelant or primer. Electricity travels on the exterior of a conductive body, not the interior. In addition to this, gunpowder is a poor conductor of electricity, so the static electricity would not arc through the powder, instead traveling along the case wall.
In addition to this, I don't believe that static discharge could generate enough heat to set off powder.