It would have helped a great deal if you had outlined in your initial post that your real concern is that the strata manager is a) taking instruction from one owners and b) refusing to let committee members see the paperwork relating to the work done for said owner.
I would put a motion to your next committee meeting that you send a letter to the strata manager asking why their contract should not be terminated for breach of their basic duties.
Actually, I would just sack the strata manager, sign up with Stratabox and manage the scheme ourselves.