Columbus Short -- CONFESSES To Brutality in L.A. Bar

Fugitive from justice Columbus Short lied when he claimed the guy he knocked out in an L.A. bar had it coming because he slapped his wife ... fact is, Columbus confessed to the guy IN WRITING.

You'll recall ... Columbus was arrested in March after sucker punching a guy during an engagement party at a West L.A. sports bar. The guy ended up in the hospital with a concussion and broken nose.

Columbus spoke out last month ... claiming he punched the guy in defense of his wife, because the man was taunting the "Scandal" star's wife, slapping her in the face with $20 bills.

But we've obtained a text message Columbus sent to the guy he hit ... sent the very same night of the incident. Columbus wrote, "I know im texting and incriminating myself but I have to own what I did wrong in that situation."

Columbus goes on, "Im so sorry and completely disappointed in myself," adding, "Whether I go to jail or not that will be the worst punishment of all. Losing you guys."