Hello and thanks for using Just Answer.
I am Al and am happy to assist you with your enquiry.
I am afraid that I would always advise clients to be brutally honest when answering the Property Information Form.
As it appears it was an isolated incident, I would hope that any Buyer would not take issue with it, but if you do not disclose it, and then the new Buyer does have to report any noise incidents, and it is disclosed to your Buyer that you have previously complaine, they would have the right to sue you for Misrepresentation. It is highly unlikely that your neighbour would disclose any previous compliant, I must admit, but it's probably not worth the risk.
I would therefore suggest that you disclose the incident on the PIF.
Sorry this is not the answer you were looking for, but it would be better to disclose, rather than face possible legal action at some point in the future (however slight this may be).
Can I assist you any further?
Sorry just to finish, can you please advise how much information I need to disclose, for example a long time ago I had to ask them to ask their son not to drop water down my garden when he was playing water fights upstairs. They spoke to him and it stopped.
Can I write that I have spoken with the neighbours a few times about their son for x and y incidents and the matters were resolved or do I need to give dates and full descriptions of what happened? If dates, I can't remember the previous incident!
It would be more than adequate for you just to say that you have had cause to speak to your neighbour concerning xyx activities carried out by their son in the years ab and c, and each time the activity ceased, to my satisfaction.
Hope this helps.