What is the mitigating factor in a case where a convicted murderer stabbed a prison guard?

I am going to quote from a decision of R v. Bernard (1989) N.B.J. 316. It’s a decision of Mr. Justice Riordon. This case was referred to the court this morning. In that case, a prison guard was stabbed and the attack was unpremeditated and did not cause serious injury. The accused in that case was serving a sentence for second degree murder and had a long record of violent crimes. The mitigating factor in that case was the fact that the accused pled guilty. The Judge in that particular case, stated as follows and the paragraphs are not numbered, so I can’t reference a number.