His ruling came at the High Court in Dundee in an examination of facts hearing – where evidence is led before a judge, with no jury.
Mrs Pryde’s bloodstained body had been found on the kitchen floor.
The court heard the 74-year-old died as a result of blunt force trauma to her head, chest and neck.
She had cuts and bruising to her face, as well as 16 rib fractures and a fractured voicebox.
Lord Arthurson said that Mrs Pryde had sustained a brain injury that was similar to those seen in road traffic accidents.
He said it was “very clear” that the attack was out of character and that the couple “had enjoyed a loving and fulfilling relationship”.
She died a week before their golden wedding anniversary.
