I think Eichel meant this to be more of a subtle, stick whack thing to get back at Kaprizov, but it ended up looking like a classic spear. In other words, it was half hearted on his part...he didn't extend his arms, aim for the face, or groin. Having said that, he tried to pass it off like he didn't know he was there, but you can see that he took a little peek just before he did it.
No extra discipline necessary. Luckily Kaprizov is all right. I think Eichel was as surprised as anyone with how it went down, but you've got to control your stick.