You said "In one of my branches of theories, Sergio was co-conspiring with a Legion member to mishandle some of the donation funds" end quote
You posted their policies on mishandling funds/fraud/embezzlement etc, I have read the same and addressed that also. The foundation, which has paid employees, who control, administer, distribute, oversee grants, etc, for major funding of the organizations that the Legion sponsors. Of course anyone caught doing anything illegal or unethical will be kicked out, employees and volunteers. This has nothing to do with volunteers/members that have no access to accounts.
They are an attraction, donating their time and investment in the required Storm Trooper costume to help other charities. Where do you see that Sergio could have his hand in the pot to steal from what account? MOO but if one is going to repeatedly bring this up, especially when you name Sergio, who has been cleared by an exhaustive investigation, a reasonable question is how could that happen? There is no funds he controls or has access to. If you understand what their activities are, where do see this happening?