EXCLUSIVE

Michael Smith -- aka Bubbles from "Trailer Park Boys" -- just got a huge break from the L.A. City Attorney ... who rejected his domestic battery case due to insufficient evidence.

We broke the story ... Bubbles was booked for misdemeanor domestic battery after witnesses told cops he choked a woman near the pool at Hollywood's Roosevelt Hotel.

Sources close to Michael and the woman tell us they're baffled the case was dropped since cops took photos of the alleged victim's bruises and torn clothing.