If the arbitration is reliable this is true.
But its a complicated subject.
DNMs often have dispute arbitration also, but if it's just some dude who DGAF scams can easily happen.
Discussion
so far i have heard of no arbitration issues. That would be a way for them to quickly ruin their network and I don't think they want to risk that. Not saying it's impossible at all, but it wouldn't make very much financial sense for them to ruin their network by arbitrating poorly.