No, I don't believe it is correct. But in order to label someone as such, some pretty heavy accusations are being made, and they had better be correct and have clear insight into the "false prophet's" heart and motives, or the accusation is a sin on the accuser(false witness). Definitely not an insult to throw around lightly. Even calling someone a "fool" is a dangerous game.
"But I say unto you, That whosoever is angry with his brother without a cause shall be in danger of the judgment: and whosoever shall say to his brother, Raca, shall be in danger of the council: but whosoever shall say, Thou fool, shall be in danger of hell fire."
"To call someone a false prophet is evidence of the accusers error"
The statement is wrong.
It shouldn't give us pleasure to expose false teachers, but the thing is, unless someone speaks out against false teachings and explains biblical WHY they are false, how can those new to Scripture possibly know what to watch out for?
Jeremiah 14: 14 YHWH replied, "The prophets are prophesying lies in my name. I didn't send them, order them or speak to them. They are prophesying false visions to you, worthless divinations, the delusions of their own minds....
Matthew 22: 14 For many are called, but few are chosen.
In other words: Not everyone receives "special words" or revelations from G-d! We must not listen to people who espouse strange things that do not line up with the Bible. We are to confront those types to let them know they are off the path and, if ultimately they refuse to heed, ignore them and put them out of your life for good, for they do NOT belong to Yahweh; they are working for the enemy....
Matthew 18: 16. And if he does not listen to you, take with you one or two others, because of the mouth of two or three witnesses, every word is established. 17. And if he will also not listen to them, tell the congregation. And if he will also not listen to the congregation, let him be to you like a tax collector and like a heathen.
Ephesians 5:11-13: Have nothing to do with the fruitless deeds of darkness, but rather expose them.
Titus 1:13... Therefore rebuke them sharply that they may be sound in the faith ...