Maybe the fault for that belongs to the company who tried to create the association in your mind by using a similar voice and tweeting about that one movie with the voice.
That’s basic advertising. They knew what they were doing. It’s just that it may have backfired.
I think the tweet was dumb but in my layperson's understanding of the law and the situation, I doubt OpenAI is at any huge legal risk here.
Even if they are able to show irrefutable proof that it wasn't ScarJo and is in fact another person entirely it will not matter.
This is one of those times that no matter what the facts show people will be dug in one way or another.