As far as I know it's not illegal to buy and sell stock in public companies in the United States of America and there are no laws that require the disclosure of all buyers and sellers of same. The real question is, as discussed in this article, did then-private citizen GW Bush use insider information to sell stock that harmed the buyer and avoided a loss for the seller. Since the stock rebounded to its pre-sale price the next trading day and doubled within 12 months of the transaction, it seems to me there ain't no reason to worry about who the buyer is unless one is interested solely in "the politics of personal destruction".
How do you or I KNOW that? I certainly don't. The only way that might be assuaged is by that buyer being known. The possible connection to Bush must be assessed. And since you note that the General Population is developing a perception on the matter, it IS a political matter, not necessarily a legal matter.
Sometimes hanging on technicalities and legal fine lines is more detrimental than disclosure. And causes a Political Hanging.