Was Dunn ever there? I don't remember him.
I was of the opinion that they never added him because, unlike the way they recruited most of their players, in a Dispersal Draft the players seem to have more ability to argue their contract. If they want the salary to be increased then they can demand it and the club has to either accept it or give up trying to sign the player. All the players signed on trade would have agreed a contract before they announced the trade, and the ones on the Expansion Draft IIRC have to accept an offer at the level they were previously at, giving them no room for manoeuvre.
While contracts can be agreed quickly, when the player is holding all the cards it can go on a long time. Dunn will know that he's got another month to get the contract agreed, and his agent will be delaying it as much as possible in order to make the club sweat it out and consider raising their offer.
That's usually how it goes in contract negotiations, anyway.