I'm not exactly sure what it is you're asking here -- but you're right that the program wouldn't have picked up the duplicate since you worded your question differently. The program will try to link words and phrases with certain posts, but it's never perfect because it can't understand the question like a person could. So while the post was hidden as a duplicate, nobody is going to see it as your "fault". We get that this happens sometimes and that people make mistakes. Nothing is going to be held against you for it -- the program's imperfections means that inevitably, situations like this are simply going to arise. (Because of that though it's probably best to do a manual search for the question if you never want anything taken down, but regardless you haven't done anything that's going to become a problem.)
Rest assured that flags and hidden posts don't have any repercussions or negative effects on you or your account. If a post is at all punishable, we (mods) will deal with it ourselves manually, but in this case we have no reason to take any action for a simple mistake. So that it's clear though, the post won't be reshown since it was resolved already, but the answer is available in the thread linked in the comment on your post.
If you have any further concerns, feel free to leave a comment on this post.