Not easier to spend than stock, bonds, derivatives, and so on that most wealth is stored in? Last I heard, there was more liquidity and less auditing for Bitcoin spending in general. An expert on Bitcoin might know that particular block moving would be a high risk operation. Thugs reading about his identity, worth, and use of Bitcoin in criminal dealings might think differently. They might decide to go get his money.
That's the risk. Not sure of its likelihood in terms of a percentage or even verbal description. It's near zero while he's anonymous, though.
