Might've been a duplicate report as well though I wasn't able to verify that that's the case.
I am 99.9% sure I didn't report that twice. I've looked into my history back then too.
I have only one post reported twice, but that's in 2 different days for 2 different problems (first it was off topic and got moved correctly, second is for plagiarism and it's unhandled).
But again, I'm not worried much. I know that most (
) of you guys (and girls?) are human and prone to mistakes now and then.