I saw the game on TV, too. I would say the catcher was only sorta blocking the plate. It looks to me like an alley to the inner half of the plate was open. Hicks decelerated greatly in the last few steps. He was probably trying to decide whether to slide or take out the catcher and hesitated so long that he did neither. But, from the video replay, it is clear that the on deck batter is telling Hicks to slide in plenty of time for him to do so. Plus, Hicks makes two mistakes after he passes Vavra, who was well down the line. You can see from the replay that Hicks briefly turns to look to see where the ball was, presumably looking to see if the play was coming or if it was going to be cut off, but either way, he should've been expecting to slide from the crack of the bat and been looking to pick up the on deck batter for further instructions. After he looks back, he then cowers a bit as if he thinks he's going to be hit by the throw. This is when he starts to slow down. When the catcher controls the ball, he and the glove are high, leaving a nice little path for a low slide.