My read on this is that A. Carmack wanted to retire, but hold on to his shares in the company (which hasn't been the previous practice at id). The other owners said no, but offered to buy his shares before he left. He wanted as much for them as they were worth to Activision, but the other owners didn't want to offer that much.
Activision would have paid a premium for id...the evil they would create from that take-over would endear them to Satan to almost the degree of EA.
So, the other owners didn't let him retire, they fired him, and counted on the previous policy (which would have forced those fired to sell their shares back to the other owners). And now it's in court. Did I get that right? I'm not good with business stuff like this.