Ann: SGH advises Watchstone Group Plc of claim under SPA-SGH.AX, page-238

You have no understanding of any of this. The claim will be a broader one of deceptive and misleading conduct against the company and likely more than the entirety of the escrow money. It isn't a claim specifically for the escrow money. Again, "Caveat emptor" has nothing to do with this in that this relates to misleading and reliance. If one is induced into purchase via misleading information it is irrelevant whether they did enough due diligence.