[OT] Two assassins plead guilty to second degree murder then try to kill each other in open court

There doesn't seem to be any video of this but two men who admitted to killing an accused terrorist fought a bitter physical fight in open court after accepting a plea to second degree murder. I can't recall ever hearing of something like this before.
https://vancouversun.com/news/guilty-pleas-murder-ripudaman-singh-malik
The article is right in observing that the killers have admitted to the killing but have only agreed to a second degree murder conviction and have not identified who hired them to do the killing. Why give them years less of prison time? Was the prosecution case really that weak?
It wouldn't be unprecedented for people who had committed an obviously premeditated murder to be be convicted only of second degree murder. I still remember the case of a serving Canadian soldier named Denis Lortie who carefully planned an attack on the Quebec provincial legislature, wrote a manifesto announcing his intentions, and then carried them out, killing three members of the assembly. He too was convicted of second degree murder. He was soon demanding escorted day paroles to go play golf - and granted them! He's apparently living quietly in Quebec having served his sentence some years back.
I'm also curious what would make the two assassins attack one another in court? That is surely not going to win them any points with the judge....
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Rhino