wonder if there indexes on their db's have become corrupted. This is somewhat similar to what I use to see as a ms sql admin when a system was brought on line that didn't have indexes. There servers seem out of sync too. Earlier I was in the manga series. One refresh would show last psot update 6 minutes ago. About 5 minutes later it would show last post updated 3 hours ago. After another refresh it would be back to x minutes.
That could cause a problem with the db's too. If they are set to sync and they could be causing each other problems if they are too far out of sync, creating a massive data transfer and update.
Wouldn't a ddos just simply create a can't reach or time out. Not database errors. Also inserts of messages and uploads taking longer seem like a db issue.
Even this message, I see it I do a refresh it disappears but page displays. DB's out of sync.
One last thought. They just brought new servers on line is my understanding. Wonder if they have something messed up with internal firewalls or the db sync not setup right.