All very believable and worth investigating further. What can I say? War is hell, especially if you bet on the loser and you’re still there. The Russians in their march to Berlin were visiting holy hell on anyone suspected of collaborating with the erstwhile occupiers. The French were shaving the heads of collaborators, even prostitutes who serviced Germans, and they were beaten in the streets. The retribution-fest lasted for years.
The end of this article mentions the ambivalence of the residents to their “liberation,” for fear the Russians will be back on top eventually. It could be there is something more in back of it that they didn’t want to say out loud.
In general, you have very vindictive people in Europe, especially in the East. Since wars are less frequent, we don’t often see it now. But it’s lurking beneath the surface. Europeans don’t have a monopoly on vindictiveness, but they definitely are into it under the right conditions.
Those eastern Europeans are the descendants of barbarians, after all.