An interesting situation.
Firstly examine whether you can do anything to reduce the noise, even if you believe you are right.
Secondly, if you believe that you are reasonable, wait for the next step from the OC. They can ask for mediation, in which case a compromise may be agreed.
The OC may decide to take it further. It’s up to the OC to prove you are a nuisance. The neighbours diary is one piece of evidence, but they would need additional reports such as police records and acoustic reports to solidify their case.
The problem may just be the neighbour and thst could be flushed out at mediation.