It could just be all the computers that exaggerate everything. When a downdraft happens these days the selling algorithms kick in and sell even more. This is either in a computer algorithm downdraft or something like you mention. Can't say.
I owned this for about a year then sold, now starting to buy back. Not that the group is exactly the same but things move in groups, right now the JNJ and BAX are moving down on negativity and the big money people are putting it elsewhere. This is more a value stock rather than hot money stock and as a guess some hot money heading out, so buy some more and wait.