The dispute arises on the claim that one of the parties was unfairly removed as trustee(s).
You are assuming there is a state or federal law that would apply in this instance to determine any unfairness. I don’t think so; but if so, it is likely that would have been brought to the judge’s attention.
My sense from the poorly written article is that they have not yet had a hearing before the arbitrator. If that is true and the award is contrary to some state or federal law, then the disappointed party can be expected to appeal with a “void as against public policy” type of argument as one of their complaints.
Excuse me, they did have an arbitration hearing and an award was rendered. It was in the first paragraph and I missed it.
So my last sentence in #26 brings us to where the parties are, the losing party took it to the judge and he found no basis for overturning the award.