[Dfbrand]

Hello all, long time peruser, first time user. I've had a botched BT install and I've had an engineer back to fix it today. I have a question and he wasn't sure. I've attached a picture for clarity.
So the socket was replaced today, the black cable on the right goes to a phone upstairs. It used to plug into the socket but he has now wired it to come directly off the socket (it goes in underneath).
The cable plugged in is an extension, into the end of it is an ADSL filter and into the filter is plugged my BT router.

My question is... as the phone upstairs is now connected directly to the socket, is it going to cause problems with the ADSL? As to be it appears that the spur going off upstairs doesn't go through a filter.

Hope this makes some sense. If you need a diagram let me know and I'll knock one up.

Thanks for your help all!