While I cannot condone bulldozing the graves... A lot of those red army soldiers fought against Estonian army. They weren't in any way liberators, just as Germans turned to not be ones.
If you weren't a Jew, you were - in general - treated OK by occupying German soldiers, and least according to accounts I've heard from people who where actually there. The Germans were professional and courteous, the Russians uncontrolled and ravaging thugs.
Funny how Russians always see themselves as 'liberators', not 'occupiers' of Estonia. If this was the case, once they'd driven out the Germans, why didn't they then leave?