The standard of proof is balance of probabilities because it's a civil case, but the nature of the most serious allegations means the evidence has to be particularly cogent, which raises the standard way beyond simple balance of probabilities, closer to beyond a reasonable doubt. Somewhere in the middle, I suppose. The panel isn't going to toss a mental coin and see which side it falls on. It will have been more like tossing a coin five times and unless the same result is achieved then forget it (yes, I know it's not a perfect analogy).
Add to that a presumption that people act responsibly and within the law, especially respected businessmen with impeccable reputations who give witness statements, and the PL better have some serious smoking documents if they want to have any chance at all of succeeding on the most serious charges. Which they won't.