Is this a normal occurrence for the dissenting judge to do?
I have not read enough dissents to have a firm opinion, but I believe it's fairly rare.
The Chief Judge did go to great legnths to show that this case was in conflict with the Classen opinion, which the Fed. Cir. issued last year. Demonstrating a clear conflict between appellate panel decisions should suffice to get the full court to review. I did not appreciate it during my quick reading of the dissent yesterday, but Judge Moore, who wrote the majority opinion in MNTA, was the dissenting judge in Classen. She addressed multiple issues in her dissent, but her analysis of the Bolar amendment was a short-form version of her majority opinion in MNTA. Judge Newman wrote the opinion for the majority in Classen, which consisted of the Chief Judge and him. I think there are 11 judges on the Fed. Cir. At this point, my preliminary vote count stands at 2 for MNTA and 2 for Amphastar.
Here's a link to the Classen case for anyone interested: