https://support.mtgox.com/entries/20323996-mt-gox-system-update-troubles
so to understand this correctly.
mt. gox performs a major upgrade live, and rather than bringing the exchange down for maintenance relies simply on mysql table locks to prevent the processing of live activity.
even though this was a major update, and the date was known for weeks, the exchange didn't put even the basic protection of halting dwolla withdrawals for a few hours so that if anything went haywire (which it did, of course), all of the funds held by the exchange would still be under the control of the exchange?
does this accurately describe the situation?
yes