Of course. And probably. But...
What are we doing when the only options being contemplated are "Drink" or "Don't Drink"? Especially when we all know that "Drink" is the option that will be popularly chosen because it's obviously better for the story? All we are saying to MM is "Go on". He could have drawn the next part of the story at the same time, in that case. We accept that he has already decided what story drivers will happen when the stuff is drunk, that's fine. No one is saying "Drink, and then x or y should happen in the vision" because we know it's already decided. That's okay, we're not writing the story. But when our contributions are basically "Go on" and the next scene could have been drawn right after the last without input we aren't really interacting with the story.
It's something MM may not have thought of to flavor what he already wants to do. Permanent blindness and pain could be a result. Or death. None of which needs to be an end to the story or make it less entertaining. It's also a disservice to MM to assume that punishment is all he has in his kit-bag when he has complete agency over events. He's hardly limited to punitive options and there's little evidence that he prefers them. Rather than "go on" let's think of things that give him options outside of the main plot already penciled in.
In this example it could be something as simple as an eye color change. Or it could be something mystical, like having eyes that can see dead spirits. Or it could impress/offend the vulture tribe and earn us the acclaimed/infamous title of Noi the Eyes of Juice. Maybe half the tribe is impressed and the other half offended, creating a vulture tribe schism and potential for political plot and antagonism in that regard. Or it could be nothing more than looking like an uncultured idiot. Importantly, any of that could happen along with whatever is already planned for the cactus-juice. We don't need to brainstorm ideas for every direction we suggest but we should try to offer directions that, with only a little imagination, leave the way open for extra plot points.
We were very close to having the bird dance idea voted down because of conservatism.