I’m not really sure his intent was to shake Crabtree’s hand...but lets say it was. How does that excuse his throat slash penalty or his rant that scared the heck out of Erin Andrews?
It doesn't excuse his behavior in any sense. He should apologize. Makes the team look bad.
Contrast with Russell Wilson, conservative Christian who tweets Scripture, and with Marshawn the silent.
Moral: some players have better character than others.