I certainly don't know much about match racing. Just wondering though, BMWO fell off (borne off) early enough to establish his new course, to clear Alinghi's sterns (2:15:29), so Alinghi can now borne off and hunt BMWO? Really? Aren't rules in place to address this? Maybe we should give Spithill some credit here.
You don't have to bear off and drive at them, you can also hold your course and ease sheets, slow down so they cannot duck so easily, to make them tack or go way below the layline. Either way, Alinghi did nothing to stop them.