I wouldn't put too much stock in that "Joint" Declaration. Many of the Lutherans (as well as others) left the Protestant reservation years ago. Please note the following statement from the Joint Declaration:
Our common way of listening to the word of God in Scripture has led to such new insights.
Oops. This is code words for, "Well, forget what is history. We decided to change our theology to suit us." This often occurs in many Catholic writings. If you would like an example just go to New Advent (the Catholic dictionary) and look up atonement. It pops up all over the place. We become "enlightened" because we have new insight. HA!
There is no such thing as different views of justification. The definition of infusion is quite clear that one has to work for their salvation. It is also quite wrong.