You could take out the "probably" and replace with "maybe" - just have a look at this very page of comments and it shouldn't take you long to find wildly inaccurate statements or anecdotal -> conclusion type theories.
You could do that, but HN guidelines ask us to assume, and post in, good faith.
Blindly assuming/implying someone didn't get their source from some kind of trustworthy place and then giving them grief for it is not a good faith comment. And it discourages people from asking questions in the future.
OP seems genuinely curious and open to whatever answers they might get. Why be a dick to them?
You are criticizing OP based on an evidence-less assumption that you have made about them.