The following is supposedly a true story relating a situation that actually occurred in Los Angeles.The Marines were backing-up LAPD on a call that someone had broken into a store.
At the scene, the cop told the
Marines to "cover" him as he approached the store (to police, "cover" means to
point your weapons in the direction of the threat, to Marines it means lay down
a base of fire!).
The Marines promptly laid down a base of fire. The
Marines fired 178 rounds before they stopped shooting.
probably a little scared at this point, called 911 and reported, "They're
shooting at me!".
But officer, I did what you said...
FWIW this is an Urban Legend or a sea story. I never found any evidence to back it up.