I've literally never heard of anyone impressed with the quality standard on a single service Comcast provides soooo...gonna call bullshit on this, too.
How can you screw up just connecting a cable modem to a coax outlet?
Run two lengths of cable connected by a four port adapter, and staple the adapter to the wall a foot above the baseboard because why not, this is only in the middle of someone's dining room.
As soon as he left I disconnected the whole mess and ran a single length of cable along the baseboard, with a right angle connector to keep it flush.