You can't put this whole package of blame on one single character. Both, Kazehaya and Sawako are equally to blame for this misunderstanding as they are both involved in creating it as well as being unable to see through it at this point but ultimately they are both lacking communication.
Add in some disctracting hits by Kent (obviously) , Chizu (telling Kazehaya he's the most distant to Sawako) and somehow even Kurumi (rekindling Sawako's doubts and insecurity) and you have quite the fine web of misleading information and false assumptions where it's impossible to clearly say which single character is to fully blame.
Tbh I think this misunderstanding is cleverly constructed and really good writing, especially if compared to how simple and boring other series' misunderstandings usually work:
"Oh gosh, pushy female side character has made a move on main male character which main female character misunderstands and thus ends up being pissed at main male character." (switch genders for shoujo scenario)
Anyway, I totally understand if people get frustrated with such a situation and drama but to some degree that's what these episodes/chapters are supposed to. Again, you can't appreciate the light if you've never been in the dark ... ok that was kinda cheesy i admit but you get the idea
