Did not Medivir CEO/co. know that JNJ/VRTX collaboration/agreement was extant prior to entering its own with JNJ? Sounds like poor dd to me, and not thinking far enough ahead.
My father was a salesman dealing in a host of school supplies, paper products and the like, calling on drug stores, groceries,dime stores and other variety stores. He presented what he had in his catalog, and the owners would make their choice, often buying more than one product from different mfrs. No problem then with supposed conflicts. The mfrs involved were the likes of Kimberly-Clark, Nekoosa, P&G, etc.
It should make no difference which agreement was in effect first.