Other Ocean was responsible for the port but Sony is at fault here for outsourcing the port to a developer which couldn't deliver the product as promised.
Game should've been fixed before release, not weeks after. Good that they're looking into it though.
Which means Sony is at least partly responsible for the port. Instead of getting Bluepoint (who has done good for Sony in the past) they went with ex Backbone staff, who mangled various PS3 ports and the MK arcade collection.