Surveillance video from a Greenwich, Conn., Starbucks will likely prove New York fashion designer Beata Boman immediately left the coffee shop after looking in her purse and noticing the fur scarf she took from a store down the block, her lawyer said yesterday.

"We believe the Starbucks video will reveal an 'OMG' moment" -- and that she was leaving to return the scarf, said lawyer Mark Sherman, who plans to subpoena the footage. "She rushed out without buying coffee."

Boman, 38, was busted Monday after allegedly boosting the $11,000 scarf from Richards of Greenwich, walking to Starbucks, and walking back to the store.

The Polish-born socialite claims she accidentally put the scarf in her bag after becoming "very emotional" during a call with a friend awaiting brain surgery, Sherman said.