It's a very sensational way of putting it, but I think all three of his points are probably true.
#1, Mikko didn't seriously think the Avs were going to trade him. He saw how this played out with Landeskog, and how it's playing out with Marner in Toronto. He didn't think it as a real possibility.
#2. The Avs were not making serious effort in trying to negotiate with the Rantanen party. They had offered Rantanen 11.25x8, and that was it. Apparently, the Avs didn't want to move past that number, or at least not near the MacKinnon number which the Rantanen camp was seeking.
#3. "The Avs paniced". Well, I suspect what he means is that the Avs wanted to make this trade now, because Canes were seriously invested in talks with Vancouver. There were only so many suitors for Rantanen, and clearly the Avs wanted Necas. So when the talks with Carolina and Vancouver picked up, the Avs decided to make the move.
I don't particularly care for Strickland, but I don't really see anything factually wrong in his reporting here.