I recently flagged one and immediately noticed that. I realized that I may have done that accidently other times too. I went in my profile and found a list of all flagged topics and I saw that I had accidently flagged multiple submissions over time.

I think it will be good to have with flagging some sort of confirmation that system asks users to confirm flagging in order to prevent unintended flagging that as I saw on my personal example happens over time and gets unnoticed.