Looks like I am n my own on this one.
The guy was banned from a certain stretch by a certain Mr Paton (no guess which beat then)
He contraveined a court judgement not once or twice, but multiple times. He was warned by the Police that if he continued, he would be arrested and a custodial sentence may follow.
He ignored that advice and was arrested for Breach of the Peace.
In court he was asked multiple times to refrain from answering back but chose to also ignore the judges advice.
He was therefore jailed for Contempt of Court. (straight from the horses mouth, not a paper or hearsay.) The sentence had nothing what so ever to do with a court case from 40 years ago and everything to do with a cantankerous old fool who showed little respect to the Judge or Court.
Various reports in the papers have put the number of salmon he was caught with, which earned him the ban between' 40+ to 60+. As the papers have proved, they are not very good at reporting the facts but a local angler in an Aberdeen tackle shop, who remembers the original case stated that this chap was extremely well known and had been caught with numerous bags of poisoned salmon over a fairly long period of time.
Make of that what you will, but I believe he got what was comming to him.