<<The way I see it, MNTA and NVS should be treated as a single person for purposes of determining the amount of damage (D) that was done by the infringement. Once D is determined it will be up to MNTA and NVS to split the amount between them according to the contract they made.>>
This came up a few months ago and I argued back then that unless NVS is actually coming out ahead as a result of Amphastar/WPI's actions, it does not matter whether you treat MNTA/NVS as a single person for purposes of computing damages, because if you consider them separately, the extra damages to MNTA as a result of the "terrible Novartis contract" is offset by reduced damages to NVS.
E.g., as a simple hypothetical, if MNTA and NVS were prior to the infringing behavior earning combined profit of 100 and were splitting that 40 MNTA and 60 NVS, and if as a result of the infringement, that profit is reduced to 30, which is shared 5 MNTA and 25 NVS, then, the damages to MNTA/NVS considered as a single person would be 100 - 30 = 70, whereas the damages considered separately would be 40 - 5 = 35 for MNTA and 60 - 25 = 35 for NVS, for a total of 35 + 35 = 70.