It's not that surprising at all, rather than that one should look more like being first or second for them as something that isn't right, I said it 5-6 rounds ago, Leipzig had the advantage of easy matches, taking a look at their 5 out 5 losses in the CL is pretty clear that any title or at least fight for that title is out of their league in Bundesliga and a qualification in CL is another wet dream.
They started nice because they had the advantage in game matching, when shove comes to push the harsh reality comes to the surface1
Fair? Common, Dortmund players could pray for a week to all the gods in the universe and they would not get as lucky as they did this time, no way the result was fair based on what happened in the field, you can point the finger at Bayern for wasting opportunity after opportunity but it's still a ton of luck for Borussia.