I agree with that. Frankly Fuhrman's opinion at least is rational. Most people who argue against the death penalty are areguing in favor of the perpetrator's right to live even if he spent his whole life killing and torturing children. Fuhrma's concern is in regard to the question of guilt.
Frankly there should be a different standard of proof before we give someone the death penalty and Fuhrman appears to be open to that, but he doesn't express it. Before we execute a criminal the proof should not only be "beyond a reasonable doubt" but the evidence should preclude the possibility that anyone other then the defendant could be guilty. In other words there should be a finding that it would have been impossible that the defendant did not commit the crime. Perhaps a secondary standard that the jury would have to reach in a death penatly case, something like, "no legitimate or actual possibility of innocence".
Some death penalty cases are really borderline in the evidence department and the heinousness of the crime often poisons the jurors minds against the defendant to the point that they wish to punish somebody and the defendant then becomes the target of their wrath.
I think Fuhrman has gone too far by suggesting that the death penalty should be abolished, but then his arguments at least have the appearancer of legitimacy.