Sieghart is right.
Actually Vegeta attacking Cell breaking Cell's focus gave Super Saiyan 2 Gohan the opening & chance he needed to win without that Super Saiyan 2 Gohan would've lost.
2. Ok flimsy! Vegeta
So Super Saiyan 2 Gohan was mopping the floor with Perfect Cell, Cell explodes regenerates & returns as Super Perfect Cell equal to a Super Saiyan 2 ?......Really?
Ok Now Vegeta gets upset & amped up & he can't go ascended Saiyan 2 ? but yet Gohan goes ascended Saiyan 2 when Cell crushes android 16's head, such BS.
A full blooded Saiyan Vegeta, who has been fighting & training harder & longer then Goku & Gohan is denied Super Saiyan 2 at that time.
It shows total favoritism for Goku & disregard for Vegeta's abilities.