Karel_x
According to the recent findings I enclosed, there was no any impact with those two birch trees. The plane flew above them and lost the part of wing 70 meters behind the second birch due to critical overload (more than 5g).
According to the Miller's report the HV lines were cut by flying tree branches. Although, it arguably happend 2 minutes ealier it should have (time of the event was registered by power plant computer).
As for the wing, there are registered cases where plane loses part or even whole wing and lands safely.