Instead he visited his mum and relied on her to tentatively keep him informed as Hibs recorded an imperious victory over Kilmarnock at Hampden.
It is an episode which rankles with the midfielder, since he was raised as a supporter of the club. It might also feel as though he missed out given that Hibs have faltered habitually in their efforts to add another item of silverware to that League Cup.
Hibs will start it all over again this evening when they host SPFL League 1 club Stranraer. The Easter Road side were spared a match in the second round of the competition as a result of their fleeting relationship with the Europa League and Thomson has attached particular significance to tonight's tie.
"I'm proud of all the achievements I've got and the winner's medals and to get one with the Hibees would be a special thing," said the midfielder. "It was hard to see the team I left win the CIS Cup in 2007. I never watched the game. I sent all the boys a message to wish them luck and I went to my mum's work, she works at a nursing home, and she said: 'they're winning, they're winning'. It was brilliant and I was delighted for them.
"You need to weigh up these things. If I could have won [the cup with them in 2007] and then moved to Rangers and had the success I had, then yes, of course, I would have. But when these opportunities come . . . I've not got a crystal ball."
Stephen Aitken hasn't needed one, with the Stranraer manager obliged to look to the past ahead of a return to Edinburgh. He was a member of a team from Stair Park which recorded a defiant goalless draw against Hibs in a Scottish Cup tie in January 2002, only to be comprehensively defeated in a replay at Easter Road.
"Stranraer defeated Hibs at Easter Road back in August 1998 in the first division but I wasn't at the club at that time," said the Stranraer manager. "This game was different as it was a strong SPL Hibs team that we faced [in 2002] with Gary O'Connor, Derek Riordan, Tam McManus, Ulrik Laursen, David Zitelli and Ian Murray all playing. It ended 0-0 at Stair Park in what was the actual game played to just after the New Year.
"The conditions were not great and the pitch was really heavy but we held our own. I had a chance early on when Kevin Finlayson played me through but I just slipped the ball past the post. We rode our luck a bit in the second half and our luck ran out early at Easter Road."