No, they each downloaded the blockchain independently from scratch. I don't know if I can replicate that crash, it was a one-off oddity. It had run for 24h+ building the blockchain then armory db without a single crash and I restarted it repeatedly, it crashed once then didn't when I relaunched it. I'll see what I can do. Since you're only asking questions despite seeing both machines' logs I'm guessing the logs were of no help?
The logs don't have the one good hint I was hoping for. On the other hand I didn't pick that the error is not deterministic at first. That's an interesting point on its own. I was under the impression the error was occurring 100% under the "right" conditions, which is why I hoped a fresh log + fresh db folder would really outline the exact error.
Have you seen any pattern in the bug appearance? What would you say is the failure to success ratio?
If you can't get it to fail when it's starting from scratch then just report it and that's about it. I'll have to get my clue from some other vector.
While I cannot get it to CRASH from scratch, both the fresh startup with no DBs and subsequent startups all do the same thing 100%: They build the DB in "silence" with the status part of the UI unresponsive, then, at some point during the Armory DB building part, they stop progressing for no apparent reason around 19-20GB size, while the disk activity continues to be intense. Once they reach that, they stay there indefinetly. Subsequent restarts of the app will show Armory catch up with the extra few blocks that popped up on the network during that time, but once they get back to building the Armory DB they again stop and they remain that way, best I've checked, for at least 6 hours. Since the initial 20GB are built in less than 2 hours, I doubt the remaining 9GB of Armory DB are actually taking that long.
The other thing to point out, again with 100% occurrence, is closing the Armory once it is in this state. The UI says a big "Preparing to shut down" on the main page, but remains stuck at that stage while still using the HDD. It takes a second go to the File -> Quit Armory for it to close, and then it does it in a few seconds. Usually when an app cannot shut down it doesn't "try harder" the second time you ask it, it either eventually does it from the initial command or it doesn't at all and has to be killed through forced end task, but in this case Armory actually requires me to issue the Quit Armory option twice in order to close.
I have checked my task manager and can find no phantom armory/bitcoind/guardian processes, so it's also not the case of a previous lingering process. I really am confused.