Endermen don't become angry when you see them

I'm able to partially confirm this. I was in a field with 2 endermen. Looking straight at both of them, well within the 64 block endermen observe radius, and they refused to acknowledge my presence. Eventually they teleported away beyond my range. This has also been confirmed by others on our realm.

I've also had plenty of endermen attack me when looking at them. It appears there is something wrong with the detection being watching mechanism that throws them off. No items were blocking view, and no transparent blocks were in the way.