>>I'm wondering if there isn't a PRIVATE type inheritance that occurs for events, where it doesn't occur for methods, such that on events the global variables are inherited from their current values, and they can be altered and manipulated in the event, but when the event returns the PRIVATE nature asserts itself so the original value before the event returns to each variable, and they are visible as they were before the events.

Don't think so. PRIVATE is really a compiler directive, not actually creating the variable unlike LOCAL or PUBLIC. Easy enough to demonstrate:

PRIVATE myvar
? myvar

If a (declared or by default) Private variable exists when a proc or function is called, it can be manipulated there unless passed as a parameter by value or declared local or private there. If the variable does not exist but is created in the called function or proc, by default it is created private to that sub-proc, so its value is lost at the end of the proc.

PRIVATE myvar
*---uncomment this to compare:
*---myvar=""
=Test()
? myvar

FUNCTION Test
myvar="I think, therefore I am."