I think the unknowns here do merit further study. Shamus apparently has a hard-on for Carmack and/or Occulus (which an increasing number of games journalist seem to have), and isn't looking at all the facts.
Things Shamus Doesn't Know
1. ZeniMax may have been working on a piece of hardware that we don't know about. The stupid line about "ice cream tech from Honda" is misguided at best and moronic at worst. Companies dabble in things all the time, for diversification, for new profit centers, and sometimes just because they can. Microsoft was a purely software company until the XBox. Then they made the Surface and bought Nokia to make phones. Sega was a hardware/software company that shifted away from a lot of its hardware after a lot of mistakes.
2. Carmack's contract may cover things he worked on with company time or resources. He could have been working on it as a side project at ZeniMax like the Sony employee Ken Kutarigi that made the Super Nintendo sound chip without the board's approval using Sony tech. (Did You Know Gaming - Playstation). We also don't know for sure if he used ZeniMax code (he claims he didn't, but that's why we have investigations, to make sure of these claims)
Things I Don't Understand
Why the ZeniMax hate, Shamus? The only real thing they have is the Scrolls patent debate which does look stupid for ZeniMax and I think was close to being settled (IGN isn't talking about it nonstop, so I'm assuming it's done). Bringing in the "buggy game" argument was also really freaking stupid. Bethesda games are ambitions and large and some bugs are to be expected in things that are ground breaking. If Carmack is as great as you praise him to be, why did they have him working on a crappy title like Rage and use him in making Skyrim or Oblivion or Fallout to polish it up a bit. Seems like poorly allocated resources.
Also, you just basically attacked ZeniMax. I know this is an opinion piece and you're not a real journalist with pesky worries about integrity, but you could have provided a balanced view.