Rebuffing a developer’s claim that one of its outside lawyers had botched a Manhattan condominium offering plan, a state judge has ordered the developer to return $16 million in down-payments.

Acting Supreme Court Justice Anil C. Singh (See Profile) rejected arguments by developers of The Rushmore, a luxury Upper West Side condo, that the offering plan drawn up by a Stroock & Stroock & Lavan attorney mistakenly included a Sept. 1, 2008, rescission date when it should have been Sept. 1, 2009.