The exes were both at Trousdale to celebrate a mutual friend's birthday when the alleged drama started.
"Lindsay went to give Samantha a hug," the insider says, "Samantha wouldn't stand up to give her one, so Lindsay threw a piece of ice at her face."
And contrary to L.L.'s tweet, our source says Sam didn't retaliate after the icy attack...
"Thats where it ended," says the source. "She didn't spit in Lindsay's face."
An email sent to Lindsay's rep was not returned.
One part of Linds' Twitter tale that is true? That Sam was hanging at the club with an unlikely friend: Miley Cyrus's ex-bofyriend Justin Gaston.
Our source confirms that the underwear model and actor is a "close friend" of the DJ's.
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