The French centre ~ just a few weeks short of his 31st birthday ~ was heading home because his pregnant wife, Stephanie, needed to be close to her family. He remembers both moments well, too.
"It was very hard to leave, but it was a way for me to say thank you to all the supporters who were outstanding for the two years. When you play team sport, it's very hard to say transfer feelings to people off the pitch. Sometimes you can clap, but I think they deserve more than that. I try to do my best and play with my heart, because Worcester was definitely in my heart."
But what few at The Rec knew about, that final day, was a chance meeting with chairman Cecil Duckworth, the night before, on the Sixways car park.
"He came to see me and said 'Thomas, I think you'd like to stay. We can have a discussion about that with John, because there is probably some solution'," he recalls. A couple of days later, at the players' dinner, instead of a speech that ended au revoir, he revealed that he was staying. More tears, this time of relief.
"The more I arrive close to our departure, I was like the man on the station waiting for his train. Finally it arrives, but he never gets in. It was so hard for me to leave. I have to say thanks to Cecil." We can all add Stephanie to that list, too.
"When she makes a decision, she doesn't come back on it. I knew that if she said to me 'yes, we're going to stay', it's okay. There wouldn't be any problem."
It wasn't the end of the emotional roller-coaster, though. As pre-season started, Stephanie gave birth in a Paris hospital, two months early. Thomas and daughter Laurie spent a few days in France, but then faced a three-week wait before baby Margaux was well enough to fly to the family's adopted home and the care of doctors at Worcestershire Royal Infirmary.
"The people were very nice in Worcester hospital," Thomas adds, "and Laurie is very pleased. It was not easy when we came back here and for three weeks she couldn't see Mummy. She was sad. But now she's good."
A happy ending all round, then, because Thomas' decision to stay has been like a new signing for Warriors. The difference is that he's already part of the furniture. It puts him in an ideal place to consider the eight, hard months to come.
"I know everyone wants us to qualify for the Heineken Cup," he smiles, "but I think it is a step, it's not a final objective. If you want to reach a step, you have to be ready. We have to remember that we're only here for two years in the Premiership.
"We lost a bit of our speed last December," he harks back to Warriors' remarkable start to the 2005-2006 Guinness campaign, and turns it into a thought for a year that's full or promise, at home and at work. "With the new signings and the biggest experience we have now, we won't make the same mistakes. We're working for the future. It's better to build on safe foundations not on sand."