I suppose anything is possible.
Kind of sucks for it to go bad like that.
How long did you crank engine over with the coil arching to the firewall? I have had the same happen (arch) on occasion but for very short intervals with out a problem.
Any chance you had a non filtered battery charger hooked up to your battery while you were cranking?
I believe all of the newer MSD's have a diode in the primary 12 volt circuit to prevent burn out from unfiltered DC voltage, but possibly not.
Is this a new or used box?
Best of success getting your problem fixed.