I wonder what was the design consideration there? If I'd to make a guess, the point of having key in a re-programmable memory (susceptible to such errors) could

I wonder what was the design consideration there? If I'd to make a guess, the point of having key in a re-programmable memory (susceptible to such errors) could be that it could be re-programmed later - otherwise it could've been just hardcoded in ROM. Athough if the error was that it was a RAM copy of the key that's got corrupt, this might explain things - no one to reboot the machine around, huh. If re-programmability was a design consideration, it is interesting is that there was no key reset procedure (with another, "master" key) which is something one would want to use if the normal communications key is compromised or corrupted.