The general managers had already talked about legislating home plate collisions out of baseball before Scott Cousins ran over Buster Posey, but that particular moment in 2011 seemed to fully define the risks at hand -- the possibility of a great young franchise star having his career ruined by an outlier play.
The rules were changed, and similarly, Chase Utley's postseason slide into Ruben Tejada in 2015 accelerated eventual discussions to protect middle infielders.
The same sort of crystallization seemed to happen last summer in regards to the universal designated hitter, with the highly respected Masahiro Tanaka.