if you call everyone dude and a transfem person gets mad about it, don't get defensive. just say like "sorry, i won't do it again" and don't argue "actually it's gender neutral" or "i call everyone dude". even if you do, i guarantee she's heard that argument from someone who very much does not call people they see as women dude. i certainly have
same goes double for the word guy.
"women are my favorite guy" 
https://www.youtube.com/watch?v=S-OgkNgxm3k
i see and hear women call eachother "guys" and "dude" pretty regularly even when there are no men in the group so it's not like my highschool spanish where the style guide used to be -os even if there was only one man. I don't think it's legitimate to argue that it's always gendered without getting into microdialects, but neither does that invalidate someone being uncomfortable because sometimes it is still gendered and of course we need to respect them.