He didn't. He was already clear with what he was willing to pay for guys (especially rentals) at the TDL.
He probably went to Davidson, asked him the price for Hagel + Fleury, and Davidson said 1st+1st+Knies. Dubas said no chance. Dubas can't do anything about other team's asking about his players.
Does not mean any of those details should be out, especially when they are that specific. I don't think Dubas is worried about the fact that Knies was included or that he was interested in a goalie (Campbell/Mrazek can't be so ignorant as to think that the Leafs would not be looking externally for an upgrade after they have been the league's worst goalies for months now), but rather that a guy who had been an official GM for like 2 weeks was incapable of following basic GM protocol.