Probably more of a meta discussion, but the reason immigration officials are no longer concerned is the fact that they have delegated that job to the airlines who don't dare to board pax that are not squeaky clean. That said the major airlines have a way of checking with the immigration authorities of the destination if they are allowed to board someone, but that won't help you when you are trying to check in with an outsourced powerless nearly min wage agent in a small remote airport. They will go by TIMATIC out of fear to lose their job if they make a mistake.