It is extremely callous to Finland to put it that way!
The USSR attacked Finland while Germany and the USSR were allies against Poland. Understandably, Finland defended itself from this attack and entered into a defensive war with the USSR. Two years later, while this war was still going on, Germany attacked its ally the USSR. Thus Germany and Finland became allies by accident, because they were both fighting the same country. As the Russians started defeating Germany, the Finns expelled the (very few) German troops that they had allowed into their territory, who had to escape to Norway (still occupied by Germany) through the north.
