As far as I know, Brandenburg banned the use of bullets containing lead because several eagles were found dead and it was assumed they had eaten game that had been shot with bullets containing lead and died from the poisoning effect of the lead.
After the ban all hunters had to use lead-free bullets and then the above mentioned accident happened. In order to be not responsible for further accidents the authorities banned the use of lead-free bullets immediately but so far it is not proven if lead-free bullets tend to be deflected more that conventional bullets.
Right now the authorities are not sure what to do and I guess they do nothing for the next years until research will show that all bullets may be deflected.

Kalunga