How do the experts pass an error up the call stack?

When an unrecoverable error occurs in a level 3 sub() and the level 1 sub() set EnableEvents = False, how do the experts let VBA know that it needs to set EnableEvents = True? Or re-protect a sheet, or reset FreezePanes, etc when necessary?

you can raise a custom error that is not handled by any intermediate error handlers. or use functions that return error or success values

I had a thread that I suspected had crashed when events were disabled - I sent code to enable events but I don't think they did - two weeks of coding down the drain