This is pulled directly from article from the original post:

"[Dr. Andrew Baker] said that if Mr. Floyd had been found dead in his home (or anywhere else) and there were no other contributing factors he would conclude that it was an overdose death,” the June 1 memo said.

That is the basis of their defense. He would have died anyways from fentanyl. What they'll do next is to say Chauvin's actions followed protocol despite rough footage from the video. Thus, the causation was fentanyl.

You're a smart guy. You know exactly what they're up to. It's their only road due to the video.

If you want question intent. Feel free. You can try to dispute the video ... but it's going to hard.

My anger towards the fentanyl issue is that I know people will try to use that as an excuse for Chauvin. Maybe that was not your intention, but it's not with most. I know I was harsh, but I'm just tired of it. The video and the medical examiner's report are clear. They concluded he was killed by the police. That's the only thing that matters unless the police attorney can dispute it.

Now if you want argue INTENT, that's a different story. You're more than welcome to try.