You do realize that by Samsung using Sony's sensors it DOESN'T prove their superiority (although I am NOT saying Samsung's are better). Samsung Electronics BIDS against competitors for the chance to put their parts in a Samsung phone. Just because it's a Samsung product, doesn't mean it's automatically used in a Samsung product. This is a VERY well known fact.
+1.
Samsung didn't use its own ISOCELL sensors because most likely they had other reasons to use the Sony sensors instead. And it probably wasn't because the Sony sensors were better in any way.