Last night, we changed our clocks in the United States (where the server lives.) This means that the hour from 1-2am occurred twice. The second time, posts could appear to be "in the future." For example, if you posted at 1:55 the first time and looked at it 10 minutes later, it would then be 1:05. The times in that thread look linear now which implies the problem corrects itself once that second hour is over.
I do vaguely recall seeing this when coding the feature. But for something unimportant that only happens for an hour year, it wasn't high on my list of worries.