the fact was that you knew but you couldn't solidly prove it
No, I suspected it, then confirmed it by checking the IP. Just because the numbers are different doesn't mean they can't be matched up. I know where you live. The proof was solid enough. You could keep arguing that it wasn't, but there's no point. Because technically nothing at all is true proof other than a mathematical formula... but a regular person would see an IP match as
solid proof.