//Luckily i had the lovely people on here to advise me at the time and following the advice i opted NOT to sign it.//
I recall that well, bednobs (something to do with your dog allegedly causing damage, IIRC). Unfortunately the police operate on the basis that the vast majority of the people they deal with are completely ignorant of basic legal principles. They may well be right, but there is no reason why people should have to acquaint themselves with legal principles in order to protect themselves from police malpractice. In your case, if I recall, the police had absolutely no chance of taking any proper legal action against you and instead went down the (dubiously legal) "community resolution" route in order to placate the complainant. They should not have done this. Instead that should have simply informed the complainant that no offence had been committed and that's that.
I suspect a similar situation has developed here where the police wish to satisfy the complainant who was allegedly on the end of a "dodgy" text when in fact no offence had been committed. They can then say "The "offender" has accepted a caution, so they admit their wrongdoing." Complainant happy, one case "cleared up", matter closed. Disgraceful really.