The argument of Mises against calculation would claim that even identical forms of aggression cannot be compared across two people if those two people have not entered into any transactions with each other concerning that form of aggression. Bryan Caplan points out in a reductio that the Mises argument should also apply to the same person at any two different moments in her lifetime, since her utility function cannot be assumed to be constant.
Tom Knapp seems to concede that the calculation problem for two forms of aggression is largely solved any time we can infer from market behaviors the respective monetary values to people of not suffering a marginal amount of those two kinds of aggression. Our $10-trillion-GDP economic/judicial system already routinely makes such calculations about almost every relevant form of aggression — through insurance markets, tort decisions, markets in protective services and products, etc. For example, Tom seems to be saying that calculation about carbon-emission as a form of aggression is possible across time and space and victims and probability distributions. As soon as Tom makes any such concession whatsoever toward pre-emptive government judgments about hypothetical inter-personal transactions that haven't actually happened, he has abandoned the Misesian argument against calculation.
The torts-based Austrian approach is quite problematic. In The Ethics Of Liberty (1982) ch. 13, Rothbard writes:
if A has beaten up B in a certain way, then B has the right to beat up A (or have him beaten up by judicial employees) to rather more than the same extent. Here allowing the criminal to buy his way out of this punishment could indeed enter in, but only as a voluntary contract with the plaintiff.
This principle obviously leaves no room for effective tort-based regulation of pollution. If I blow cigarette smoke in your face, I'm hardly deterred by the threat that you will sue to to punish me by blowing an equal amount of cigarette smoke back. If you abandon strict eye-for-an-eye retribution, you immediately mire in the quicksand of calculation.
In For a New Liberty (1973) ch. 13, Rothbard violates his own retribution principle and Austrian calculation theory by envisioning class action torts against polluters. But even this would be inadequate, because while class actions may work (inefficiently) against individual bulk polluters like factories, there's no such thing as a class action against a whole class of polluters who each pollute at levels far below the cost of individual enforcement.