The Federal Circuit court has stated the legal duty as follows—a person with actual notice of another’s patent rights has an affirmative duty to exercise due care to determine whether the person’s acts will be infringing, including the duty to seek and follow competent legal advice before beginning activity that may constitute patent infringement
That point will easily go to MNTA/Sandoz, as they would obviously get a legal opinion before launching (and would certainly not ignore an adverse opinion).
Recovering Treble Damage: The "willful" infringement of a patent enables the plaintiff to collect treble damages, as well as attorneys' fees. The burden is on the patent holder to prove under the totality of the circumstances that an accused infringer acted willfully. Whether the accused infringer obtained a competent opinion of counsel is now simply one factor to consider in this analysis. Other factors include:
• Whether they deliberately copied the ideas or design of another (ideas and design would encompass, for example, copying the commercial embodiment); • Their behavior as a party to the litigation; • The defendant's size and financial condition. • The closeness of the case; • The duration of the defendant's misconduct; • Remedial action taken by the defendant; • The defendant's motivation for harm; • Whether the defendant attempted to conceal its misconduct;
Most of those elements would also lean in favor of MNTA/Sandoz. The deliberately copied clause might go for TEVA, and the defendants financial condition would go for TEVA.
As this is a totality of the evidence situation, I think that the issue is not even close (assuming Sandoz does not override their lawyers opinion and launch regardless).