Firefox isn't hoisting based indirectly on spec.
This can be circumvented by not using function declarations and instead using variable declarations (which I believe do get hoisted in all browsers).
If so, I don't think that will circumvent the issue since only the variable declaration will be hoisted, the function being assigned will probably not be. You'd end up with 'not a function' like error when invoking instead of undefined.
EDIT: Actually, I'm not sure if your last sentence is talking about the problem in the article since the person your reply was to has deleted their post. If it isn't, then disregard.