Look at it this way - of the following, what's more serious
To plan to kill someone?
or
To plan to kidnap and confine someone? And so happens they get killed.
Because those are the two different types of 1st Degree murder charges.
Maybe you're comparing this case to the Bosma case? If so, the two are different. Here there's a ton of evidence proving planning and deliberate intention to murder in the Garland case.
It doesn't matter which is more serious - my point being - a death that occurs during a kidnapping or unlawful confinement is first degree murder. The jury HAS to know that that is a road they are allowed to take to arrive at a first degree murder conviction. Even if they believe all the murders were planned and deliberate - they still need to know this option. And one of the biggest questions is - was nathan's murder planned or spontaneous? If the jury finds it was NOT planned - they can still find him guilty of 1st degree, if they believe he was killed while unlawfully confined, and or kidnapped - both which the Crown contends happened. It's crucial information for the jury. And if the judge does NOT allow for them to find that road to 1st degree (like in the Bosma case), he must instruct that.
I'm hoping the others are correct in that he just hasn't got there yet.