MLB says Anthony Rizzo was in violation of the Posey Rule

Anthony Rizzo's slide into Padres catcher Austin Hedges was a rule violation, writes Ken Rosenthal at Fox Sports:

Major League Baseball, according to sources, informed both clubs Tuesday that Rizzo was in violation of Rule 7.13, which the sport introduced in 2014 to protect catchers from such collisions.

The violation carried no practical consequence; plate umpire Jeff Nelson ruled that Rizzo was out to end the sixth inning of the Cubs’ eventual 3–2 victory. The outcome would have been the same if Nelson had invoked the rule, which is why the play was not subject to replay.

In this Paul Sullivan article in the Tribune, Rizzo says he didn't do anything wrong:

Rizzo didn't think it was a dirty play, of course, saying he went "pretty much straight in." He apparently should've tried to slide to the outside of the plate to meet the exact standard of the Posey Rule, in which case he also would've been out, and then he'd be criticized for not doing whatever it takes to win.

I can see both sides of this argument. Theoretically, once the catcher has the ball it's anything goes; however, the Posey Rule is supposed to prevent things like that from happening. And I do understand the point of the rule, which is to prevent serious injury.

Hedges had to leave the game with a thigh contusion, which hopefully isn't anything serious. As noted in the Rosenthal article, there hasn't previously been any discipline for this kind of rule violation, so I wouldn't expect anything here either, except perhaps a fine, and maybe further clarification on exactly what a runner coming into the plate can or can't do.