In the case of a liquid, or partial liquid evacuation (such as was noted earlier by someone) one might estimate a displacement or volumetric effect in the level of water in the bowl, and again, comparing it to the dental molding casting after it is submerged in water (Archimedes was the first to develop this method) a positive ID could still be made.
The granting of a pardon is an imputation of guilt, and the acceptance a confession of it.
