Sorry - no answer. Just the same question. Common Apple! This is ridiculous - you're supposed to be the experts at usability! Did nobody at Apple foresee this obvious need to go back to search results? You "only" had 20 years of Web search engine behavior to draw inspiration from!
I Love Siri, but with the constant shortcomings versus the Google voice search app, I'm getting pretty fed up. At the moment, Google's voice recognition is MUCH faster (is it the Apple servers that are too slow?) and it doesn't suffer this basic UI design flaw. If Apple didn't make it so difficult to swap out Siri (and maps for that matter), I would have swapped already. Since I can't, I'm relegated to whining here in the hopes of shaming Apple into improving its products faster.
Common Apple, how basic a thing to miss!