Like people who say Dutch let Kreese strangle Johnny when turning his back just don't know what they're talking about.
Dutch was his friend and likely only did that because he was disgusted by the situation and couldn't believe what Kreese was doing to his friend.
He also probably was scared of Kreese and felt forced to obey him and not intervene given how deep he was in the cobra kai mindset.
Like if Dutch truly didn't care if Johnny died, he would not have left the dojo along with him and the others immediately afterwards when they left.
And he certainly wouldn't have continued to hang with them and remain close with them in the years after high school like he did.
But since he did all this, this should put things into perspective that he might actually have cared for his friends.