Hindered by not being able to see your pictures but:

#1: The 358 Norma Performance. I for one would use that bullet again although as you say the penetration could have been better. Despite the
Poor performance of the 270 caliber partition I'd bet that a 250 Partition bullet in .358 would have expanded a bit less and penetrated a bit more.
My beef against your bullet is purely cost and availability in Canada.

#2: The only Nosler partition I have seen act like this is an 85 grain .243 or 60 grain .224 when hitting something really hard, really fast. (ie not an animal). I have had the 85 grainers self distruct when hitting a gravel strewn backstop for instance. The bullet is bent with the back lead squirted out...obviously having taken an enormous side impact.

I am at a loss as to why the bullet acted like this. I use the similar 140 Partition in my Ruger 6.5 Rem Mag and have always had complete penetration on caribou even when taking an angling shot or against shoulder bone. I'd have full confidence in this load even at close range against moose. In fact even the lighter 125 partition in my REM 660 in 6.5 Rem mag has completely won me over. Could this be a one in a thousand incident of striking angle and tumbling or is there lot-lot variations in construction quality that could explain this? A rib shouldn't stress the bullet like this but it obviously did.

I'd pull one of them and section it to see what you are up against.