Steve Young started a season with 6 interceptions at Georgia, and went on to have a great year.
Robbie Bosco threw 2 or 3 interceptions at Pittsburgh on his way to an undefeated season and national championship.
Ty Detmer, Heisman Trophy notwithstanding, threw a lot of interceptions.
I'm not saying Retzlaff is any of these accomplished quarterbacks, but we shouldn't be looking for perfection and calling for his head. They won the game, afterall.