What is important to note is that PADI does not alledge a standards violation. PADI does not say that the instructor did anything wrong, and above all, PADI does not say that the standards for student control are inadequate.
Is there more information somewhere about the actual incident? I read the document posted, and from what I read (entirely possible I missed something) the instructor's lawyer said PADI had provided no explanation for the expulsion. But that was pretty much it. Did I miss it in the document, or can you point to other proceedings related more specifically to the incident?