(TMZ) - Shaquille O'Neil got one of those dreaded parking boots on his truck - and all he had to do to get it removed for free was choke out the dude who did the the booting ... TMZ has learned.

TMZ reports Shaq was playfully strangling Spence Beck of ABS Booting in the video he posted on Instagram Tuesday night - but it was all the boot man's idea.

Spence tells TMZ a few hours after he slapped the device on Shaq's ride outside an Atlanta restaurant (someone forgot to feed the meter) ... he got a call, and instantly recognized the Diesel's voice. 

According to Spence, Shaq played his cop card, saying ... “I’m a U.S. Marshal, I need you to remove this boot."

If you didn't know ... Shaq really was deputized back in 2005 when he helped feds track down sexual predators - and that was good enough for Spence.