very odd. yes it appears that the server had a hiccup and prematurely ended the raid. this means that CanUndo returned true when it shouldn't have. this just can't happen under normal server conditions
i've seen this happen on rare occasion over the years. I'd like to try and fix it, but I think I'm chasing a rabbit down a hole
how many plugins are you using?
what is your entity count?
how often do you restart?
do you have an item leak? an item leak can increase memory usage, cause performance issues, in turn causing the server to behave oddly
are you using a shared or dedicated server?
do you have plugins that remove loot from containers that might contribute towards this problem?
do you know if the user saw the event "Destroying raid base at in X minutes" message?