HELP. Plagiarism concern in dissertation

So I recently submitted my dissertation, my Turnitin similarity was 15%, all 1% matches or less with random sources (pretty much most were topic-specific common phrases and fragments of sentences). However, one problem I noticed was I summarise the research method of a paper which I cite in text with year and author name, but I appear to have summarised it (one fairly long sentence) in a way that is similar to how that author did in their own introduction (must have read this introduction and subconsciously taken in that sentence). essentially it's just a bad paraphrase of a bit of a sentence which has been cited and referenced. Turnitin partly matches bits of the sentence but not all of it since it is not a complete word-for-word copy.

What are the likely punishments for this if it is brought up? Or has anyone done something similar?

Thanks a lot in advance