https://www.cbc.ca/news/canada/what-s-the-difference-between-1st-degree-murder-2nd-degree-murder-and-manslaughter-1.5068520

Honestly, I think they might even be rolling the dice on second degree. Yes, there was planning. Yes, it appears to have been "intimidation or criminal harassment" (both under first degree). Intent is the thing here. Since the victim didn't die for many days, and since the two were also arrested on robbery charges in the wake of two other incidents with other people, it's plenty arguable by the defense that they didn't intend to kill the victim.