Glocks rarely jam, atleast mine never has, so considering “extended mag” ususlly means some after market higher than average cap that comes with pistol from factory, I can think of a few msg brands thst might cause an issue like that.
That fact probably saved several lives…. Gee, did the guy have a pistol permit? Where did he get the Glock from, and the extended magazine? Gun law in NY sure worked wonders, didn’t it?