Litigants’ failure to specify which set of Board of Realtors’ rules governed arbitration in their case revived an agent’s suit against a Sotheby’s International Realty colleague she claims squeezed her out of a $27 million sale.

Licensed real estate agent Dragana Connaughton sued to recover $470,000 in damages, alleging Palm Beach broker Cristina Condon cheated her out of the lucrative deal. She claimed she brought the property to Condon’s attention, but got no commission for the sale. She sued Condon, colleagues Jean Lembcke and Susan Wright, Sotheby’s International Realty Inc., Sotheby’s Inc. and Realogy Holding Corp., which does business as Sotheby’s International Realty.