I agree on the PI, with the caveat that I lack any scientific background. I did find quite helpful the posts by RockRat, iwfal and poorgradstudent on the BV board earlier today, which gave me some understanding of the issues addressed in the MNTA memo. I was encouraged by the fact that PGS was able to describe Amphastar's use of MNTA's characterization process based on his scientific knowledge and the explanation of the process in the '886 specification, which should make it difficult for Amphastar to prevail on the enablement issue.
Here are links to 2 of the posts (which then can be tracked to find their remaining posts)