Mas eu não cliquei em Responder, cliquei em Editar

[JammyDodger]

Na verdade, parece ser o plugin Post Voting.

Acredito que já exista um tópico UX sobre isso:

Change 'Answer' button back to 'Save Edit' when editing a Post Voting post

When I edit the original topic the button that would normally say “Save Edit” now says “Answer”. It has the functionality of save edit, or seems to, so as it is currently I find it misleading/unhelpful/confusing.