It's not really an appeal, because the application wouldn't be finalized yet. The visa officer would send them their procedural fairness letter saying that they think the person may be inadmissible pursuant to A40, and explaining why. That would give them a chance to reply. If after receiving the client's submission they still thought they were inadmissible, they would then go to the unit manager to concur with an A40 finding before refusing the application. That's sort of internal to the process prior to refusal.
On November 26th, 2012. See this statement in context.