I agree with Kibbelah on most things, but not this one. They drugged him, which means he didn't consent to anything, which means it wasn't betrayal. He can't control what enters his bloodstream.

Now, with enough faith, you actually can. You can believe the poison doesn't affect you because the Emperor stops it from affecting you and that becomes true if you believe it hard enough, but that level of faith is not expected of some random naval officer, that's a Sororitas or living saint level of faith. So getting mad and calling him a betrayer because he's not supernatural is kind of silly.

But I'm trying to do a dogma playthrough which means I just click on the dogma option for the points.