I don't see this judge dismissing the case or entering a directed verdict. The most likely scenario is that the trial will continue until the jury reaches a verdict or it hangs.
Personally, I don't think we'll ever know who killed John O'Keefe for sure. If KR is found guilty some people will always believe she was framed. If she's found not guilty others will think she got away with murder.
They'll eventually be articles and books and podcasts each with their own theory of whodunnit: whether that's Karen, Brian Higgins, one of the Alberts or even some other person who's never been mentioned to date.
People are still trying to figure out who killed Jon Benet Ramsey and that's been almost 30 years.
I don't know how it feels inside the room. Outside, I still feel have unpleasant feeling about KR, but logically, I would not have the strength to vote "guilty" if i were the juror. I can't trust solely my intuition in the absence of solid evidence, and this case reminds me of haphazardly executed quilt, nothing more.
Now, it is interesting that you have mentioned JBR case. What made that case non-solvable, JMO, were two factors. One, that JB is a smart, logical person and a good planner. Nr 2: horrible initial investigation of Colorado LE. They were so much in awe of the house and its wealthy, influential owners, that they never performed good initial investigation. And we always read, the first hours matter the most. This, IMHO, doomed the case.
But, I think people have an idea of what had happened to JBR. An accident, a hysterical mom who wanted to protect everything else she had (she already had the diagnosis of ovarian cancer), and on top, media hysterics which probably won't be that abundant today because the photos of a child, heavily made up and dressed like an adult, look horrible. We, the society, have changed. Now, lots of people made money on books and shows, but the case did ruin many lives. Patsy, dead. JB, a successful businessman, never realized his full potential afterwards. BR I wouldn't envy either. We don't know who killed JBR, but there are no winners in the case.