If his content was original in the first place, I see no reason why he used a plagiarism detector. Using a detector means you know the work isn't yours. Originality and uniqueness should be your work, not some else.
It is simply by sharing your personal thoughts on the subject or item.
100% true. When am confused or stuck on what to write, I read through others' posts to know their understanding of the topic and from there I get inspiration to write my own post.
He probably felt overwhelmed to make a post but still, that is no excuse to plagiarise. Am sure he must have learnt his lesson now and know what it means for a piece to be unique.
RE: BEING UNIQUE DOESN'T MAKE IT ORIGINAL || HIVE REWARDS ORIGINALITY