Broders - because some of us believe that they shouldn't be able to trade at all at the moment? And even if they are within their rights it seems like a very strange time to sell given the expectations!
Seems to me to be a very pertinent topic to be "psychoanalyse"ing!!
Personally I wouldn't find it very interesting at all if it was (say) Fidelity selling. However we are talking about our single largest shareholder whom have been content to sit dormant on their 18M shares for years all through the rollercoaster that is PRM. Of all times to start selling, they pick now on the eve of an expected settlement where we believe that sanofi themselves will pay out a substantial sum!! How can you not find that unusual? It is far from trivial as you seem to suggest?
Another interesting point is that if we get the news that most are expecting, the resulting rise in the sp (and hence Sanofi's asset value) will largely balance the amount that they are hopefully about to pay out!