you should have used VPN to download mate, or maybe even a proxy like v2ray. the thing is they notice your ip address when you are torrenting (cuz when you engage in Torrent you reveal your IP address publicly, to everyone downloading the thing) and send a lawsuit to your ISP with your IP address written, you ISP gladly reveals the IP is yours and sends the lawsuit to you so that you can prepare for the case. So if nothing comes from this I would say they didn't notice you.
funny thing is, since HADOPI was defunded, you can literally torrent like a madman without a VPN and no one will ever bother you, because the very thing supposed to stop people like me was defunded by the EU! Its nuts lol, but its also really damn convenient, I do keep it hush hush and only torrent sparsely and rarely, and never big files.