I favor the first case. Without making a series of assumptions and running them (I am too lazy to do that) I would venture a guess that MNTA can take 60% of market revenue before SNY would consider launching an AG. The further they take market share beyond that the greater the chance of an AG.
Taking too much of the L market certainly was a factor in the decision of SNY to launch the AG.
Timing suggests that aL approval was the trigger. But with mL up to 59% of the market it was a hair-trigger.
ij
It is astonishing what foolish things one can temporarily believe if one thinks too long alone ... where it is often impossible to bring one's ideas to a conclusive test either formal or experimental. J.M. Keynes