Hi,
I hope this is not a question from any of the mock practice questions J
The contract is between the Performing Organization and the client. It is not between the Project Managers of both companies. The guy who signs the contract will usually be authorized by the company to sign such legal papers on behalf of the company. The signing authority will usually be the Corporate Counsel or senior finance guys in each location. (Differs from company to company)
So incase a client sues the PO, it will be against the company and not against the PM. Internally the legal of your company may ask you the clarifications though.
Incase if there is a NDA breach, I have seen that, companies sending legal notices directly to the employee. Eg: Employee joining previous employer’s client where the client is common to both the companies.
Regards
Moby