Recently, I wrote a short story that contains a flashback in the middle that was used to explain a major plot point in the story. Does a significant scene set as a flashback break up the flow of a short story (usually considered to be somewhere between 1,000 and 15,000 words, depending on who is asked), and if so, why?
It's all about context. I don't think there's a blanket answer. An Occurrence at Owl Creek Bridge is, in a sense, a flashback in the middle of the story, but it works exquisitely.