I occasionally run a tor node. Was I for sure running a tor node several months ago on the day I supposedly was chatting in just dice with the same IP as someone calling themselves "dmf"? I don't know, it's possible, I do occasionally run a tor node.
How are you so certain that that was even the real DMF? Because he used that chat handle?
As has already been shown previously in this thread you haven't been running a Tor relay or exit node when chatting on JD at the same time as dmf. In contrast to JD you can't reuse usernames on MP, and espringe confirmed that dmf on MP is dmf from DN.