AI goalies are only responding to the chances you give the other team. Being out of position will increase the likelihood of your opponent scoring. Being overly aggressive and puck chasing will increase the likelihood of your opponent scoring. It's not like EA programs goalies to miss goals. Their movement, reaction time and even their save animation choice is somewhat dependant on what the humans on the team are doing.
This is the reason you see the constant, never-ending complaint of "Our team has the crappy goalie and the other team's goalie is lights out". Some of you cope by claiming EA just programs it this way, but that's completely untrue and is just avoiding the root of the problem.