[GreyingJay]

I would submit that "there is no I in team" applies here. If this person did something on behalf of the team, with the team in mind, while he was a member of the team, then it could be argued that "the team" did it. I, as a software developer, work for a particular company, and the products are sold and attributed to "the company", even if I quit.

I don't think this would be in question were it not for the unfortunate spin that the team and the individual appear to have parted ways on negative terms.

That being said, I have found that when only one person champions something, and that person leaves, one of two things will happen. The rest of the team will pick it up and keep going (making the claim legitimate), or, with nobody who knows how to keep it going, it will eventually disappear.