Do you think they should be prosecuted (if they are still alive)? If not, why not?
Absolutely not. There is a reason those people were hiding in a forest. The reason is because of those German soldiers. Had the soldiers found the Bielski group unprepared, and beaten them, then every single person in that forest, the men, the woman and the children, would have been killed, some in horrific ways.
Most likely, every member of the Bielski group had already lost family members to the Nazis.
There is no way you can compare the actions of the Germans in the Holocaust, who systematically set out to kill every single Jew bar none, to the actions of a few desperate, probably half-starved people who were simply doing their bit to help the war effort.
The important thing to note is who began the cycle. Had the Germans not persecuted and massacred the Jews, then those Jews wouldn't have been in the forest, and those German soldiers would never have been killed.