Especially when it's not the first time he's had to address the rumor and did so in a much less convincing fashion than last time.
Brad Stevens, 2017:
"I don’t speak to the rumor mill or anything else, but I’ve made it pretty clear I’m going to be here. I’ve been asked about that quite a bit and my answer will be the same — I’m going to be here until the Celtics decide they want to move in another direction"
Brad Stevens, 2021:
“That’s nice of them. It really is,” he said of all the adulation. “That’s home. I get it. I appreciate all the nice sentiments. It certainly doesn’t go unnoticed, and it’s certainly very kind.”...“I am not" (quitting the Celtics to go to Indiana)
Those don't seem like the same thing at all to me. If that was any of us asking out our significant other for the first time, pretty sure we'd be circling back as many times as it takes until we get answer #1.