The RODs in Essex South & Essex North (MA) now have a policy where they make a notation in their records if a change was made to the index due to an indexing error.  Prior to that the examiners kept a note book  with mistakes found.  If the records are online & available to copy then I would say make a copy of the page with the mistake for your own records.  Note though that I know of a case where the ROD misindexed a mortgage & the examiner  who missed it through no fault of their own was held accountable for it anyway.  The attorney in that case argued that it was the examiner's duty to examine every mortgage when running a property  owner regardless of what address the Registry indexed it under which makes sense on an individual homeowner, but in this case the property owner was a land baron of sorts who owned many,  many, many properties.  The Registry, of course, assumed no liability for any error.  Most of the examiners I know, including myself, have a statement at the bottom of their title reports disclaiming any liability for Registry/Probate Court indexing errors, but I've never seen that statement put to the test.  My understanding is that if you're not incorporated or working as an llc & you own your own home then you might just well be screwed to the wall, even with E&O coverage if you miss something.