Good question, thanks. I guess the safest and most obvious course would always be to conclude there might be corruption after an event like that and to run DBCC CHECKDB.
But I would disagree -- well, "quibble a bit" -- with your final statement "I wouldn't expect many to know error state 6 - but that piece isn't critical to the puzzle. "
It's true that knowledge is not critical, but knowing that someone pulled the plug on running CHECKDB the first time makes it imperative to re-run it. It also tells me that the first run's message of "terminated abnormally" isn't a statement about the database integrity (even if we aren't out of the woods yet). Too bad that CHECKDB didn't return a more helpful message.