This does not qualify as a "spontanious discharge", the firing pin struck the primer due to the effects of the magnetic field and the inertia of the gun striking the machine.
This same thing happened here in Colorado some years ago only the pistol did not discharge, A security guard did a similar move and his Beretta was pulled accross the room into the MRI machine, The Beretta was de-cocked; when a Beretta 92 is in the de-cocked position the firing pin is pointed away from the primer.
I also remember an incident where a fire extinguisher was pulled into an MRI machine, striking and killing the patient.
NRA Lifetime Member Since 1999
"I ask, sir, what is the militia? It is the whole people except for a few public officials." George Mason