Because this deal has so many contingencies, BMRN has smartly furnished a flowchart that shows the various paths which can be taken re opt-ins and milestone payments. (This is the chart posted by ghmm on the BMRN board with digital enhancements for readability.) Items displayed in purple are the ones deemed most likely by BMRN.
“The efficient-market hypothesis may be the foremost piece of B.S. ever promulgated in any area of human knowledge!”