I think they are baffled as to the motive. Even the victim is baffled. Everyone is baffled.
Motive? They don’t need no steenking motive. Or, as Richard Pryor learned from a brother while performing at a prison...
Pryor -— Why did you break into the house and murder all those people?
Inmate -— Well, they was home.
You are no doubt correct.
Admittedly, the event presents a very complex factual pattern. There are perhaps good local reasons not to speculate or rush to unfounded conclusions. This, of course, may even outweigh a detailed, in-depth consideration of the obvious.*
*"Hughes didn't let go of her phone, even when her attacker bit her hand."