The source is unimpeachable. Allan Glasser, to whom Tab was married.
On my Blu-Ray, he says "Fosse."
My VHS, Laserdisc, DVD, and Blu-ray all say "Fosse."
Well if it says Fosse that's the take they used. But there is a Bobby take. It's on youtube.
The subtitles say: "That was terrific Fosse."
Not that the answer matters to anyone other than the person listening to it, but subtitles are subjective and rely on the vagaries of the person doing the transcribing. They aren't an official anything.I'll go with the subtitles.