While the world is being turned upside down in Auburn Hills now, this is hardly the first time Joe Dumars has almost pulled the trigger on a trade for Allen Iverson. Back in 2006, Dumars was a guest on Chad Ford's ESPN podcast, and he told the story about how he was this close to getting AI in 2000:

How close is this close? Close enough that Dumars had already called Roundball One’s pilot to meet him at the airport in two hours to pick up Iverson. The proposed four-way deal, which would have cost Detroit Jerry Stackhouse and Jerome Williams, fell apart at the last second when Matt Geiger, of all people, refused to re-work a trade kicker for the deal to work within the salary cap.

Moral of the story: it's not done until it's done. Even if everyone in the world is reporting it and Roundball One is warming up on the runway, there are too many moving parts (Geiger's trade kicker, McDyess not wanting to switch teams to be a "ring chaser") to take anything for granted.