Richard Pratt died free of an ongoing prosecution due a kindly act by a Federal Court judge. Justice Donnell Ryan agreed to reveal his ruling about the admissibility of some key evidence against the dying businessman, even though his reasons weren’t yet ready. Those reasons, released yesterday, reveal that Pratt’s final solace only came about because his judge made a big mistake.

It turns out that Justice Ryan never ruled on whether or not the businessman was tricked into admitting his perjury to the ACCC. Instead, the judge ruled in favour of Pratt on a technicality. There’s nothing wrong with that, except that he got the technical rules totally wrong.

His mistake was analogous to a waiter applying a rule that says “Animals forbidden. Guide dogs excepted” by keeping humans out of a restaurant because they aren’t guide dogs.

The boring details: the judge was applying evidence law, which decides whether evidence gets into a courtroom or not. The law is all about rules and exceptions to rules and exceptions to those exceptions and so on.

The basic rule is that all relevant evidence is in. But the hearsay rule says one sort of evidence — representations — typically are out. But then there’s an exception to that rule for some sorts of representations: admissions are in. (Even that exception has exceptions, including the fair play rules that Justice Ryan never got to discuss.)

The judge ruled that Pratt’s statements to the ACCC weren’t representations at all, because they were just said to settle the claim, rather than to speak the truth. Whether that’s right is debateable. But what aren’t debateable are the consequences.

If Pratt’s words weren’t representations, then they weren’t barred by the hearsay rule. Just like people aren’t barred from the restaurant. Whether the words were within the admissions exceptions (or the diners are guide dogs) is beside the point.

Justice Ryan’s reasons include a note saying that they are hurried and incomplete. So, maybe he would’ve realised his mistake if he had more time. But, unless he changed his whole approach, his conclusion would then have had to have been that there were now very few reasons to exclude Pratt’s words from the courtroom.

And that means, had Pratt had his day in court, it would probably have been the job of a jury, not a judge, to decide what the businessman’s words actually meant.

No-one has emerged from this whole tale smelling of roses. But the body with the most egg on its face isn’t the federal consumer watchdog or prosecutors. It’s the federal judiciary. As Adam Schwab predicted in Crikey on Tuesday, this is a repeat of the Elliot fiasco.