I doubt that the 9.5 (which is still an awesome score) had anything to do with the PS3 version being a little late. It's more likely that there are simply not that many Cons to name, so being late made the list.
Having said that, bias for a reviewer probably has nothing to do with the console the game is played on unless there are technical bugs from a shoddy port or something similar. Bias will probably be more apparent in licensed games and certain genre titles. I mean, the reviewer that only reviews sports games is going to give a JRPG a lower score than a reviewer that cosplays. That's where you find legitimate bias for reviews, not the fanboy console war nonsense.
Having said that, bias for a reviewer probably has nothing to do with the console the game is played on unless there are technical bugs from a shoddy port or something similar. Bias will probably be more apparent in licensed games and certain genre titles. I mean, the reviewer that only reviews sports games is going to give a JRPG a lower score than a reviewer that cosplays. That's where you find legitimate bias for reviews, not the fanboy console war nonsense.