Old wood not removed from roof

I am highly upset. I had my roof done last September. It was a clear understanding that old wood be removed. As I am remodeling a room I discovered the new roof on top off the old termite dry out old wood. Was the roofer supposed to rip out the old decking before putting a new roof? I wonder what is supporting the roof??

What does the contract specify?

If the plywood was already existing, then the contractor would not have any idea that the underside was rotted. Not unless they went in the attic before the project. If they installed the plywood on top of the existing plank decking, then I see your point.

Contractor should have replaced some, if not all, rafters. Appears the plywood was installed perpendicular to, and didn’t even butt on the rafters. Is there any code enforcement where you are?