Which seems more likely: that a semi-auto firearm would cycle well enough to completely eject a round without stove-piping, but not enough to strip a round from the magazine, or that a firearm with e.g. a ten-round magazine would be described as having a "fully loaded" magazine if it had nine in the mag and one in the chamber [I don't remember the actual capacity of Mr. Zimmerman's pistol]? While I suppose certain firearms might possibly short-cycle as described, and Mr. Zimmerman might have had such a weapon, it seems more likely that the language of the report was chosen to make clear that the firearm could not have been fired twice since it was last loaded, than to describe an unusual malfunction mode.