Yeah, sounds like a bs claim to me. Thing is, most all contracts ARE legally binding by default, though certain provisions in them may not be legal or enforceable either as they are written, or in the jurisdiction in question.
This is why I include the verbiage in mine about questionable provisions:
16. All attached riders are an integral part of this contract. This contract will supersede any other contract. If any part of this contract is illegal or unenforceable, the remaining provisions of this contract will remain valid and enforceable to both parties. This contract constitutes the sole and only agreement between the parties hereto and currently sets forth the rights, duties, and obligations of each to the other, as of this date. Any prior statements, agreements, promises, or inducements made by any party hereto, or agent or representative or either party hereto, which are not expressly set forth in this agreement, are of no force and effect and shall not be considered valid or binding. This contract shall not be enlarged, modified, or altered except in writing by both parties and endorsed hereon.
Just let that one go - if they're going to be like that up-front, chances are they would be a nightmare to work with anyway.