I don't think that he said that more than one organisation was carrying out due diligence did he?It's the 'due diligence' claim that make this likely to be bollocks, it's highly unlikely that more than one organisation is conducting due dilligence at the same time.
Normally, due dilligence is done once an agreement has been reached and is done simply to make sure that the numbers match those on which the agreement has been based.
It's basically just a final check, not something you do before making an offer.