Well said, JT! Petard is unfortunate to have a nutter for a neighbour. Most people’s reaction on learning that an irrationally disliked (or deservedly unpopular) neigbour was planning to sell would be to place no obstacle in their way. As Cromwell said to the Long Parliament,”You have sat too long here for any good you have been doing. Depart, I say, and let us have done with you. In the name of God, go!”
On the other hand, if one finds a selling or letting agent blatantly misrepresenting the Owners’ position (e g acceptance of one well-credentialled dog on strict conditions being made out to be ‘open slather’; the shiny new floorboards ‘meet all the requirements of strata’ just because the timid deaf old lady downstairs hasn’t complained yet; sure, you can use your garage to store surplus furniture because the visitors’ area is there for you to park the second Range Rover). However, in such a case, it would be better to write to the agent(s) concerned, with copies to be kept on the Managing Agent’s file for inspection by a potential purchaser undertaking due diligence.