I'd be willing to say that the officer may have put his finger behind the trigger, instead of under the hammer. That's the only way I could figure he got his finger broken- either that or just in the torque of the perp trying to wrestle the gun away.
That's the problem now a days. The perp already did time for MURDER, along with various other crimes, and yet still walks the streets.
Too many hardcore criminals are let out all the time, and they are trying to take away OUR guns ????
Saw it once on Dragnet....Bill Gannon jammed his thumb between the hammer and frame as he wrestled with a bad guy. Looked like it hurt!