Land Registry ID Forms - checks to make?

Firms are beginning to report receiving telephone calls from the Land Registry who are seeking confirmation that the conveyancer who purportedly signed a Land Registry ID form in connection with a registration application did indeed sign the form. It seems that, following this initial ID check made by the Land Registry, it then serves notice on the unrepresented party itself to double-check that the transaction is authentic. In one case heard of recently, the ID form turned out to be a forgery. A buyer who acquires title on the basis of a forged disposition, and succeeds in obtaining registration, may be safe from subsequent rectification of the register if it qualifies for the “proprietor in possession” protection of the LRA 2002, provided that it has not contributed to the mistaken registration through its own fraud or lack of proper care. However, if the Land Registry is checking that the conveyancer who signed an ID form did indeed sign it, it must be easily arguable that the buyer who relied on the ID form without carrying out its own check that the named conveyancer did actually sign it may be guilty of a lack of proper care?