Russians' conflicting behavior - spoilers

Some people are having trouble understanding the behavior of the Russian troops. First they are the good guy liberators, then they are the bad guy marauders, then they are the good guy rescuers of the wounded.
(1) The Russians were out to seek savage vengeance on any Germans they found.
Czechoslovakia had the longest occupation by Germany of any European country, six years. The country was full of retreating German military and there were also the inevitable civilian "collaborators." In addition, the Eastern part of Czechoslovakia, Bohemia, was largely German in ethnicity, and there were ethnic Germans living throughout the country. All of them were at risk from Russian troops.
When the Allies liberated the country, the Eastern part was mostly taken by the Americans, the Western part by the Russians.
Tens of thousands of Germans rushed to the West to surrender to Americans, because they knew the alternative. I have a German friend who as a child fled from the advancing Russians with her family, to get to the Americans, because the Russians were destroying everything German, people and property, including the livestock. "They even threw the bee hives into the lake!" she said. The Russians passionately hated the Germans. Germany and Russia had signed a "non aggression pact" in 1939, but Hitler had violated it in 1941 by invading Russia. The German assault on Russia was horrific, including the Siege of Stalingrad. When the Russian Army came into German-held Czechoslovakia, they proceeded to kill every German they found, civilian or military. That's why in the movie, the Principal tells the Russians who have killed the priest, "he's not a German!" and as the Russian troops are approaching the Old Mill, the local leader (someone said it was the mayor, but I thought it was the school principal) keeps assuring them, "they aren't Germans; they are our people!"
So part of what the Russians are doing is looking for Germans to kill.
(2) The wholesale shootings that go on after the liberation party night are just a realistic portrayal of what happens when soldiers have been in harsh conditions for a long time, are drunk or hung over, and their libidos get the better of them. They are looking for sex, they are used to violence, and their rapes lead to attacks on them by men protecting the victims, which leads to counter-attacks. The sound of shooting inflames the half drunk Russians, who then go into combat mode, and everyone becomes crazed, paranoid, and trigger happy.
(3) After this mayhem has gone on for a while, another part of the advancing Russian troops, who are under better discipline and control, come to help the hidden villagers (as long as they aren't German).