Randal Williams, actually.
I wouldn't be surprised if the lack of surprise onside kick in Madden 13 was simply an oversight in transitioning back to the right-stick kicking mechanic; remember that Madden 12 used the three-button press kicking implementation, and the surprise onside kick was reliant on the third button press.
What I'd venture to guess EA did was just port the right-stick kicking from NCAA without regard for the surprise onside kick, which was never a highlighted feature and in-fact was something Ian Cummings added in during a weekend in his free time, as detailed by that year's Super Bowl blog.