The asset (Bain) might have been purchased (or by now sold) without the knowledge of the owner--Romney's wife.
Or perhaps Romney doesn't abide by what must be DU common opinion, that a wife can only act on behalf of and with the explicit permission of her husband, especially in fnancial matters. Wives have no independence of any kind. That's just because they're wives, I guess. (/sarcasm)
Or perhaps Bain didn't check with a minor investor over whether the purchase a share of the Chinese company was was okay.
It's even possible that between the reporting period included in the August '11 filing (which would probably not include August '11) and when the Chinese company assets were bought the fiduciaires disinvested in Bain. Unlikely, but possible--esp. considering the debate over Bain last fall. I don't know if fiduciaries should take into account the non-investment interests of an owner's mate.
But most importantly, if the trust really is a blind trust, then Romney's wife would not be informed of the holdings in her investment account. If she got a copy of the filing, she still wouldn't have the authority to order the sale or purchase of any asset. "Blind trusts" are to prevent conflicts of interest: If you own shares in Solyndra then any vote or policy that influences Solyndra is a conflict of interest. That might involve a lot of issues, some of which you might not even spot until it's on the front page of the NYT. Blind trusts mean that even if you voted on Solyndra you'd have no idea if it benefited you.