Obviously, he had none. As for the law itself, it was an amazingly bad one. Tinkering with appellate review procedures to affect the outcome of one case ought to boggle the mind of anyone concerned with the idea of "rule of law." I now understand why the U.S. Constitution prohibits Bills of Attainder.
"Bills of attainder, ex post facto laws, and laws impairing the obligations of contracts, are contrary to the first principles of the social compact, and to every principle of sound legislation. ... The sober people of America are weary of the fluctuating policy which has directed the public councils. They have seen with regret and indignation that sudden changes and legislative interferences, in cases affecting personal rights, become jobs in the hands of enterprising and influential speculators, and snares to the more-industrious and less-informed part of the community." - James Madison, Federalist Number 44, 1788.
Every legal expert has agreed on that at least,it was not a bill of Attainder.
A Bill of Attainder is a law that *adversely affects* a single person or a small group of people. Laws that *benefit* a single person or a small group of people are commonly referred to as boondoggles (IIRC) and are by no means unconstitutional; in fact, they are very common. The law passed by Congress granting de novo review of Terri's case certainly was not a Bill of Attainder.