No. Correcting someone and stating facts isn't rude at all. However, since we are in a forum and we can only read and not hear the voice of someone, just hearing facts can sometimes come across rude. I'm sure that was no ones intention, but I know the feeling.
What helps (at least it does help me): Just remember you always learn something when someone corrects you. You build up knowledge, you can appreciate worlds creatures even more and you are a more educated person from one second to another. I think this is pretty awesome about this forum and the game. So maybe that helps you with it.
As someone who is sensitive to language I still think, everyone would feel more relaxed if we can put facts into more than one sentence. It helps with not hearing the tonation of something, in my opinion.