Pointing out a mistake can be pointy
When pointing out mistakes made by other people, be sensitive. They may be a newcomer to the community of people participating in your forum or editing the same wiki as you. They may not understand all of the jargon, and they may be embarrassed about it. Also, you may be incorrect, and they may not have made a mistake at all. They might find it upsetting to be accused of making a mistake by someone who is mistaken about the mistake.
When on the receiving end of criticism for a "mistake", try not to take it personally. The "mistake pointing person" is probably trying to be helpful, so it's best to assume that they are. If the "mistake pointing person" is being obnoxious about it, seek help from other members of the forum/wiki you are participating in.