Mike Dailly, principal solicitor at Govan Law Centre, was commenting on the saga of Happy Valley Road in Blackburn, West Lothian.
The Herald reported yesterday that four homes were built on a strip of land not owned by the builder and sold two years later to a developer.
The legal profession has denied any liability for the failure to deliver a clear title of ownership to the families.
Mr Dailly, a former Law Society committee convener and now a member of the UK-wide Financial Services Consumer Panel, said: "If conveyancing rules don't require a solicitor to ensure there is a valid title that must be changed by the Law Society of Scotland, or if needed by law reform.
"This particular case illustrates the irreconcilable conflicts the Law Society of Scotland has. It is the regulator of legal services and is charged with promoting the interests of both the public and solicitors. How can it do that?
"Almost all jurisdictions around the world have a separate regulator and allow solicitors to choose a trade body to represent them. Scotland is in a timewarp on this, and unless we break this conflict problems will always arise."
A spokesman for the Law Society of Scotland said: "We work hard to maintain the highest possible standards within the solicitor profession and ensure robust systems of consumer protection are in place.
"We also make sure that consumers of legal services are properly represented within the society by involving non-solicitors on our governing council and all of our regulatory committees. This ensures the public interest runs throughout our decision making."
The society said it did not get involved in claims against its master insurance policy.
Its indemnity insurers Royal & Sun Alliance (RSA) have been involved in defending two legal actions which were aimed at resolving the problem but which never came to court and are not active.
Mr Dailly called on the company to sort the case out.
A spokesman for RSA said: "We are aware of the ongoing dispute in relation to four properties at Happy Valley Road. The matter is the subject of ongoing litigation and as such we are unable to comment on the litigations themselves or on the disputes at the heart of the litigations."
Mr Dailly added: "There is a wider public interest here. It would be wrong to allow the owner of a strip of land in situations like this to hold homeowners to random.
"There is a cogent case for minor amendments to compulsory purchase law to enable Scottish local authorities to step in where there has been a genuine technical mistake, to facilitate a market value for strips of land or servitude rights in the public interest.
"If there was such a power it would likely not need to be used, but would prevent developers from cashing in on genuine mistakes."
Jack Anderson, director of developer Crannog, which owns the strip of land, said: "We knew there was a boundary issue when we purchased, but saw the potential for developing what was a part-complete site. We therefore bought the strip 'at risk' without any guarantee of return."
Mr Anderson said it was wrong that solicitor negligence had to be proved in such cases.
He said: "There should be provision for immediate compensation by an insurer in the event that the offending solicitor 'just gets it wrong'."