https://www.cbssports.com/nfl/news/juju-smith-schuster-injures-vontaze-burfict-on-blindside-block-and-everyone-is-furious/JJSS is an offensive player (in multiple senses), and isn't in a position to play recklessly in a way that dishes out wanton injury to other players. It's really hard for someone who plays offense to be viewed as a "dirty player", unless you're like an OL who gouges eyes and such.
But that’s all you’ll find. That’s the basis of his opinion.