If it's a correct PEX system with a homerun back to a manifold for every fixture, then no, it has nothing to do with any other faucet in the system. It is pretty peculiar that it involves both the hot and cold (are you SURE it's both?). Is this one of those prefabbed laundry reccesses that came with the valves in a package, like from Oatey? That's the only way that I would think that both could be defective at the valves. There's just no way that a plumber got two defective valves from a supply house. And, if it's the valves, and not the joins that are leaking, it's not the plumber's fault.

After the phone call to the insurace company and the flood restoration company, the next phone call should be to the builder. He needs to know about the faulty component. You should still be under the 12 month warranty that his insurance should cover for the damage. The call to your insurance company is for them to make sure he does the right thing.