Summary: No matter how deep one digs, based on publicly available information and even rumour mills of IBM insiders/pensioners, it is exceptionally difficult to understand what happened inside IBM's top-level boardroom/management, resulting in many departures, including Whitehurst's
Due to technical issues, the video I had recorded about this didn't work out well (focus on wrong part of the screens), so I've converted it into audio (not much was lost, it mostly showed the contents of the articles below, in turn). The short story is, it's difficult to know what exactly happened... and we dare people to tell us with certainty, rather than just speculate. We're all ears and we welcome any insider account, though we recognise that it likely requires high-level access (the ordinary Red Hatter won't be told the full story; shareholders are told face-saving stories/narratives). ⬆
The pages/articles the audio above (it was a video originally) being alluded to are: