Retzlaff had 4 options on that play and saw something in the matchup that he liked. He locked in on the fade and threw an errant pass.
A-rod didn't send in a call called "throw the fade" like you might be imagining from your intermural days at backup QB.

The "speed option to the short side of the field" was not the original play call. Sitake confirmed in his post game interview that Retzlaff audibled out of the original call. He must have seen something he didn't like.

"throws short of the sticks"... really?