Best is to follow the FR threads on this one. The guy appears to have had a carry gun on him and, again, there are major differences between police accounts and eyewitness accounts of the story. The problem seems to have arisen with a COSTCO employee noticing the carry pistol somehow or other and coming unglued over it.
My former law partner once represented the NYC Police Union, PBA.
Among his cases was one wherein a witness sued when he saw
a police officer hand his gun to another officer,
and that witness became incontinent upon sight
of the unholstered gun.