True, the copyright chose is never obtained by the thief in the sense that the thieft gains exclusive rights to enforce that chose, however the ratio of Hilton suggests that obtaining the chose is not required.
While transferring a bank balance transfers the prima facie right to sue from the victim to the thief, the victim essentially retains that right in the same way that the orgininal copyright holder retains their right to enforce their copyright - it is a right that can be affirmed in court if the the thief contests the ownership of the chose.
In that sense, then the copyright can be said to be 'touched' - the copyright is specific to that particular piece of work and is, in the eyes of the law, held by the thief and not by the victim. Like the bank balance, there needs to be a determination as to who owns the copyright.
Hilton, if it is construed widely, suggests that actually taking the chose, by transfer or otherwise, is not required for there to be an appropriation. All that is required is that the chose is interacted with in some very minor and intangible way.
I'll admit that this is all pretty weak, but interesting nonetheless.