World Series, Game 1

[Big Slick]

Originally Posted by PSUchem

We're not talking leap; we're talking crowhop, which is still illegal in ISF.

ISF: definition crowhop; 6-3-g,h; also in bold in the "points of emphasis" for 2010.

Not a crow hop (under ISF, which is quoted, or any other rule code):

Sec. 20. CROW HOP. (FP ONLY)
A Crow hop is defined as the act of a pitcher who does not push off from the pitcher's plate to deliver the ball. THIS IS AN ILLEGAL ACT if the pitcher steps off the pitcher’s plate, thereby establishing a second impetus (or starting point) and then pushes off from the new starting point and completes the delivery.

For this to be a crop hop, she would have to push/begin from somewhere other than the pitcher's plate. However, lifting the pivot foot is a separate violation:

i. In the act of delivering the ball, the pitcher may take one step with the leading, non-pivot foot simultaneous with the release of the ball. The step must be forward toward the batter and within the 61.0cm (24 in) length of the pitcher's plate.
NOTE: (h-i) It is not a step if the pitcher slides his foot across the pitcher's plate, provided contact is maintained with the plate and there is no movement backwards of the non-pivot foot. Lifting the pivot foot off the pitcher's plate and returning it to the plate, creating a rocking motion, is an illegal act.

Therefore, she could have been judged to be illegal, however I'm sure the umpires used this guideline under the ISF Points of Emphasis on Pitching:

Either foot may slide across the pitching plate but cannot lift off the pitching plate. Clearing the cleats to enable the foot to slide is not considered to be lifting the foot or to be losing contact with the pitcher’s plate.