That is absolutely correct.And if the hearing one gets contradict Scripture in any way shape or form- it is a revalation not from god. It is that simple. the Spirit would never contradict or alter Scripture. It is impossible for Him to do so!
But then if there is any issue, it shows a departure from scriptures--which works BOTH ways. The matter simply remains one of understanding, and the examples are many BOTH ways. Many have been right, and also wrong--BOTH ways. Meaning, it is all still under the care of the Spirit to reveal where and when He wills, where no man of his own knowledge is qualified to say one way or the other; and there is no actual contest, only the age-old spiritual war.