anybody is wellcome to check my findings and the sources, they are in the Stadt Archiv of Bamberg.
I was in the room where the "accident" did happen, and I walked the streets where the Russian troops passed through Bamberg and I tried to spot the windows from where it is possible to see them, for example looking up to the Residenz and see what windows I could see.
In my view one has to step at least on a chair or even into the window to have a good view at the Russian army, otherwise you will see only roofs, Berthier had done this already for two days.
I trust the police report because it lines up well with the event as it happened.
Neither the Bavarian police - or better police of Bamberg - nor the Russians had any motivation to assasinate Berthier - what would be the reason?
He was save in Bamberg, the events already were surpassing him, he did not even for once try to escape - and in his personal papers - nothing was found to indicate that he was in communication with Napoleon.
Berthier was treated with outmost honour from the Russian officers the days before the fall, they stood death watch when his body was placed in the Elizabethen church.
End of my story.