It's not the proof that but how!
This evidence does not show that Samsung copied the iPhone. Granted. However, it shows something else: The methodology on how they went about it.
The infringement part are the icons being close copies, design, etc. I'm not gonna go into detail there. It's stated and posted over and over.
Now, Apple has to establish why and how Samsung copied and this is the smoking gun for that. Samsung documents showing the iOS with direct comparison before a design change towards iOS is pretty convincing to me.
Also, there are alternatives Samsung did not use: Leave Android generic, use other contrasts, shapes, and colors. It might be that Apple used the most intuitive color schemes for certain things like green for call and red for hanging up. Piont being, Samsung copied things to a detail that even if you don't have a patent, it could be almost a copyright infringement. If I use a sythesizer making me sound like Brittney Spears and sing "Hit me baby one more time" as close as possible the same way and try to sell the records, I'm pretty sure, I will hear from her lawyers even if I got the rights to sing the song etc. If I make a rock version, not so much. What I try to illustrate here is that you can do something right without blatant copy. Now, Bell and Reis both invented the phone independently. Both didn't know of each other and both didn't claim the other one copied. That would have been different if one would have had documents comparing the other one's design to the own one, don't you think?