Luka Doncic got the boot from an important Lakers game Tuesday night ... because an official with a quick whistle couldn't delineate fan trash talk from referee chirping.
The bizarre scene all unfolded in the fourth quarter of L.A.'s road tilt with Oklahoma City ... after Doncic hit a floater in the lane to give his team a 108-107 lead.
After making the basket, the 26-year-old turned toward the crowd and began mouthing off -- but a ref thought the chatter was aimed at him .