Exactly–and this is where universalizabiltiy comes in, too. This is like a sort of boomerang thing; the aggressor cannot escape. However he formulates it, he ends up condemning his action and/or outright consenting to punishment.
SEe, e.g, n. 31 to this piece: http://mises.org/journals/jls/12_1/12_1_3.pdf
Any other similar argument of A’s would also fail. For example, A could defend himself by asserting that there is no such thing as free will, so that he was determined to murder B, and thus cannot be blamed for doing so. However, note that the estoppel theory nowhere assumed the existence of free will, so such an argument is irrelevant. Moreover, if A is correct that there is no free will, then C is similarly predestined to do whatever it will, and if this includes punishing A, how can it be blamed? The logic of reciprocity is inescapable. As Rothbard has pointed out, the Thomist philosopher R.P. Phillips has called such a type of axiom a “boomerang principle . . . for even though we cast it away from us, it returns to us again . . . .”
also n.24:
“If a skeptic were to object to the use of moral concepts here (e.g. wrong, should, etc.), it should be noted that it is the criminal, A, himself who introduces normative, rights-related terminology when he tries to object to his punishment. A similar point is made by Randy Barnett in a different context. Professor Barnett argues that those who claim that the U.S. Constitution justifies certain government regulation of individuals are themselves making a normative claim, which may thus be examined or criticized from a moral point of view by others.”
and n. 39:
“Of course, values are subjective, so damage can never be exactly equated. … But again this is not the victim’s fault, and if her only option is to attempt to measure or balance a difficult-to-balance equation—e.g. by trying to equate somewhat quantifiable physical aspects of force, such as the magnitude and type of force and the physical consequences thereof—she cannot be blamed and the aggressor may not complain. … Further, if the aggressor A were seriously to maintain that force against A and force against B were wholly incommensurable, he could never meaningfully object to being punished—for to object to punishment (force used against A) A must maintain that such force is unjust and that some level and type of force could be justly used to prevent his punishment. But this implies at least some commensurability. If A really maintains incommensurability, B may take him at his word and posit that B’s punishment of him justifies no retaliatory force on his part—which means that A is not effectively claiming that he has a right to not be punished (for rights are legitimately enforceable).”
As for burdens of proof and the like, see note 49:
"Many crimes would have established or generally accepted levels or at least ranges of permissible punishment, for example as worked out by a private justice system of a free society, and/or by specialists writing treatises on the subject, and the like. … No doubt litigants in court or equivalent forum, especially the defendant, would hire lawyers to present the best arguments possible in favor of punishment and its permissible bounds. In a society that respected the general libertarian theory of rights and punishment developed herein, one could even expect lawyers to specialize in arguing whether a defendant is estopped from asserting a particular defense, whether a given defense is universalizable or particularizable, when the burden of proof for each side has been satisfied, and the like.
With regard to the concept of making a prima facie case and switching the burden of proof from the plaintiff to the defendant, Richard Epstein has set forth a promising theory of pleadings and presumptions, whereby one party who wishes to upset the initial balance must establish a prima facie case, which may be countered by a defense, which may be met with a second round of prima facie arguments, etc."
For more “boomerang” type logic, see:
note 14:
“another way to respond to a rights-skeptic would be to shoot him. If there are no rights, as he maintains, then he cannot object to being shot. So, presumably, any rights-skeptic would change his position and admit there were rights (to be able to object to being shot), or we would soon have no more rights-skeptics left alive to give us rights-advocates any trouble.”
Finally, for more on this, see my post:
[Quotes on the Logic of Liberty]
(http://blog.mises.org/archives/007967.asp)