By that logic, every contractor hired mainly by government would have to behave like a public organization. I don't think that leads to sensible conclusions, and it's redolent of after-the-fact justification.
You say that like it's a bad thing. In fact, on major criticism of outsourcing and privatisation is that it becomes way to shelter dubious activities from Freedom-Of-Information requests that would apply if the work was done by a public organization.