The video below is not new, but it is relevant. Among the profitable things in it, these men remind us how the ninth commandment must inform theological polemics. “You shall not bear false witness” means that you must represent your opponent’s view accurately. It also means that you must not confuse your opponent’s view with an alleged entailment of his view. You can warn about a potential entailment of his view, but you cannot legitimately accuse your opponent of holding the alleged entailment if he explicitly rejects it.
For example, I might believe that Arminianism entails open theism. Ethically, I am free to make the case that Arminianism entails open theism. But I am not free to accuse Arminians of being open theists–especially when my Arminian friends disavow open theism. I might argue that they are inconsistent, but I cannot rightfully charge them with open theism. If I did, I would be bearing false witness.
By the way, this works in reverse. My Arminian friends might believe that my view makes God the author of evil. They would be free to make the case that my view entails that God would be the author of evil. But they are not free to accuse me of believing that God is the author of evil–especially when I explicitly deny it. They might argue that I am inconsistent, but they cannot rightfully charge me with believing that God is author of evil. If they did, they would be bearing false witness.
The golden rule applies to theological polemics. Do unto others as you would have them do unto you. If you don’t want to be unjustly accused of holding a position that you do not hold, then don’t do that to others. Describe your opponent’s view fairly, and don’t confuse his actual view with what you perceive to be an entailment of his view.