I have. A guy I was shooting with had a saiga 12 and either fired 9/10 rounds in the mag, left a round in the chamber before inserting the next mag or somehow loaded 11 rounds into a 10 round mag. He thought he shot all of them (these guns don't lock back on empty) and happily smacked the butt of the gun on the ground. It went bang. We all pooped a little. Did the trigger move? Maybe. All I know for sure is the firing pin hit the primer and nobody's hand was near the trigger.I've witnessed 3 separate negligent ( trigger press , thought gun was empty) discharges. I've never seen a gun fire with no trigger manipulation.