There wasn't a whole lot of reliable information out there as to what happened with Jose Calderon before he took off for Dallas. For all we knew, the Pistons could have made an offer to Calderon and he refused after a bad experience during the second half of last season, possibly not seeing a change in sight. My own hunch based on his coy responses leading up to free agency was that he didn't want to return.
Calderon suggested differently before the game on Sunday [via Freep]:
"They were in contact with me, but I think they were waiting for Josh Smith, so I was just waiting and waiting, and Dallas came with a great offer ... I couldn't say no to that," Calderon said Sunday before the Mavs faced the Pistons. [...]
"I thought they would have came at me with an offer, but at the end of the day, free agency, how it works, you wait and wait and wait until the offer is there," Calderon said. "It was never there for me to say just yes or no to make a decision."
We don't know the Pistons' side of the story, and Calderon could have still decided no, but I don't see why Calderon would lie about the situation. Either way, this pretty much just affirms what many Pistons fans assumed to be the case -- Joe Dumars wasn't savvy enough to even attempt to retain the best pure point guard he had since dealing Chauncey Billups, because he was too busy offering an ill-advised contract to Josh Smith.