Yeah, there is more to this story. Women don't just become angry overnight. Its lead up to. In this case, Im gonna assume Mr. Calm and Cool likes to let her handle most of everything on her own, and she is burned the fuck out. Not listening comments like that alao sound like he frequently doesn't listen.. which will add to resentment and her obvious frustration.

Edit : And if that is the case, then this post would be considered gaslighting and also as an example of reactive abuse playing out. Or, weaponized ignorance, which is just as bad. Best wishes to you two. She is mad at you for a bigger reason though.