As for the particular claim regarding the start menu, What he actually claimed is that his implementation was removed in production builds. However, at the same time, there's no evidence of it in any of the various Beta and release candidate versions of NT4. Not only that, but prior to the NT4 betas, it was effectively the NT 3.51 "Desktop Shell Update" and none of the releases of that have his claimed implementation. So when and where is it?
He states "I wrote the programmatic version in '94 and we ran it internally". The issue is that there really was no "NT4 beta" at that point in time, nor any start menu in NT to add his rotated text code to. It was only around the start of 1994 that what would be known as the Taskbar and Start Menu really appeared in Chicago milestones- we know he isn't referring to those, since 9x didn't support the needed LOGFONT structures. What would become the start menu on Windows NT only appeared with the "Newshell" project which was preview software that you installed on NT 3.51 to add the Windows 95 enhanced shell. originally a desktop update for Windows NT 3.51 which started around the time of 95's release in, well, 1995. There's no evidence of his special code there- in fact the NT 3.51 Desktop Shell Update previews all used a bitmap.
And you might think, ahh, hew must mean before that, but the rotation feature in question, I believe, was new to NT4 altogether- so it would presumably have appeared somewhere during the betas.
The problem with his claims seems to be that evidence never seems particular forthcoming. When new information comes out he retracts claims and re-titles videos in order to move his claim into "gaps" where his claims are less falsifiable.