[Luke]

Thanks for your comments, John. It seems like a reasonable hypothesis that "machinegunning" might result from the absence of a leaf spring on the sear bar.

I think in this case the actual mechanical operation allowed the sear to move so far out of the range of the firing pin that it never cocked at all.
However, if the sear were only partially engaged it might, indeed, allow rapid fire or unintentional discharge.

Regards,
Luke