I feel I am not getting real answers here.
Despite my recent Festivus grievances against you, I find myself siding with you in this situation, holmes.
You didn't just randomly accuse or belittle Rrhain, instead you provided extensive documentation of what you saw as dishonesty, and asked for a rebuttal. I'm not sure how you could have dealt with the situation better, and it seems like the admins can't come up with anything better, either.
I've found myself in similar situations as you did with Rrhain - even if you choose to "walk away", it is more than frustrating to later come across said poster repeatedly using the same evidence and tactics that were clearly demonstrated to be unethical. When these issues aren't resolved, they can seriously impact the forum as a whole - for example, a couple of weeks ago, it seemed randman brought up the same (repeatedly refuted/unsubstantiated) Haeckel's embryos arguments in every thread he could find, dragging multiple threads off-topic at the same time. I believe admins admonished him in some of those instances, but it simply continued elsewhere, or at other times. In many case suspension doesn't seem to help, as the unethical behavior simply resumes post-suspension.
Sometimes people need to be called out for unethical behavior beyond the thread where it occurs - especially when they use the same unethical tactics across multiple threads.
One common criticism in this forum is that the "evos" don't call each other out for such things as faulty arguments, failure to provide evidence, and dishonesty. In some cases these criticisms are valid. If these faults are seen by admins and they choose to censure the "victim" in the situation, or the person that points out these faults, then something is obviously wrong.
Perhaps the thing I find most inappropriate about the closing of your thread: Rrhain was never given a chance to defend himself. Quite unfair to Rrhain, regardless of whether or not he was very much in the wrong.
The thread could be reopened at least temporarily as a Great Debate between you and Rrhain - if the issue doesn't clarify itself in the first dozen posts, then shut the sucker down.
Hell, repost it in the Festivus Grievance thread - seems very on-topic there.