Lipkin Gorman v Karpnale Ltd [1991] 2 AC 548Lord Hoffmann explained the unavailability of an action for conversion on the basis that a claimant could not by electing to trace turn the defendant into a wrongdoer. Instead, the only action that was available at law was an action for money had and received. Such an action is not proprietary: i.e. it is not based on the premise that the plaintiff has title to the money in question. Instead it presumes a personal obligation to make restitution. One consequence of this is that the claimant’s right is weakened in that it is susceptible to the defence of change of position. This was apparent in Lipkin Gorman where the defendant was able to rely on the defence to reduce its liability to the net enrichment it had received from Cass after taking into account winnings that Cass had collected from the Casino.