Betty Ford staffer Dawn Holland is speaking out about her recent altercation with rehabilitating starlet Lindsay Lohan...

The employee reveals to TMZ that on Sunday, December 12th, Lindsay and two roommates arrived home late at night after curfew - the group even tried to jump a wall to avoid being seen!

Holland claims she was called to perform a breathalyzer test on Lindsay and company, "which Lindsay refused to do. She was very angry, out of control."

Holland then says that Lindsay pushed her and went inside the house (where she was staying) and called 911. Holland then picked up another phone inside the house to speak with 911, but Lindsay "kept yelling and cursing and screaming" in the background.

Finally, Holland claims Lindsay "tried to snatch the phone out of my arm. She grabbed my wrist and snatched it down and twisted my arm and my hand."

Holland - who now wears a cast due to a "severe sprain" - then went to the emergency room and is currently on workers' comp.

And had Lindsay definitely been drinking that night? "She had alcohol on her breath," says Holland.

Furthermore, Holland insists she "did not touch" Lindsay.

The 24-year-old starlet recently moved to a different sober house - still run by Betty Ford, but a different house with a different staff - and ditched the BF security team for a private team. This incident is likely the motivating reason behind both changes.