Makarov is a double action semi-auto with a "decocking" feature. It's specifically designed to be carried with the "decocker" off and one in the tube.
With the decocker/safety "off" the hammer is physically blocked from contact with the firing pin. BUT, the firing pin is free floating rather than spring loaded. If dropped from the top of the Empire State Building or from a 747 at cruising altitude -- with a soft primer -- the intertia MIGHT make the gun discharge.
But the gun would have to land on the muzzle, in which case you'd have a hole in the floor. I've been shooting since 1957 and haven't dropped a gun yet. Nor have I been around anyone who has dropped one.
People get struck by lightening (or win the lottery) too . . . What are the chances?