[Rich]

Originally Posted by M Anthony

It was an illegal side.
"Illegal slide (rule 2-32) Interpretation is that the runner must be able to reach the base with a hand or foot or it is interference. Can't roll block or throw cross body block "
View the slow-mo here
2012 MLB Postseason | NLCS Game 2: Cardinals on Holliday's slide - Video | MLB.com: Multimedia
An obvious body block.
The base runner should have been ejected.

Ejected? This isn't a kiddie game here.