"Apologies fans."
Then he wrote: "Genuinely excited Bodene Thompson has signed with NZ Warriors hard working and a great attitude."
What a shambles. Or is it? Watson, a late adaptor to social media, may be trigger-happy with the tweet button, but he's no fool.
Foran is off contract at the end of next year's season and is said to be one of the most sought-after players in the game.
"My gut feeling is the deal will be 100 per cent done," said sports agent and promoter Dean Lonergan. "The only thing they're waiting on is signatures on the contract. Eric Watson does not make a tweet saying 'Kieran Foran welcome to the club' if he's not there."
But the Warriors' head of recruitment, Dean Bell, told The Diary: "We're interested in all quality players who are available and Kieran is one, but we have not signed him."
Perhaps tellingly, Watson has made no attempt to remove the tweet.
For a man who once shunned media intrusion into his private life, the 55-year-old has taken to social media with aplomb, maintaining his own Facebook and Twitter accounts.
He posts family snaps of his four sons and wife Lisa Henrekson, a former fashion model. He plugs his various business ventures, congratulates Kiwis doing well, and vents his views on politics, sports and even feminism.
Watson has cleverly used social media to his advantage. This week, he showed his humorous side, posing for a Halloween pic as the delinquent Kubrickian character.
His blonde wife donned a brunette wig and a leggy Wonder Woman costume, and teenage son Sam dressed as American Psycho's Patrick Bateman. The photo was posted to Instagram.
Yesterday, Watson took to Twitter to plug two horses he had running at Ellerslie. "Princess Michella a good bet and Palace Rock in with a chance," he said.