From 70o to 90o has been "added" to the damage model. Before the patch, any hit at an angle of 70o to 90o = 70o.
I think part of the confusion in people's minds is "what is 90o?
It is straight down. (Isn't it?)
A perpendicular hit to a tank, i.e. right in the side, ---------->, is 0o IIRC.
Or, maybe I'm the confused one.
wrongway