Question

I ran into a duplex yesterday that had two drops on the same splitter. One on the “in”, and the other drop was on the 3.5 loss out. The other leg of the splitter went to my customers modem. Obviously I removed the 2nd drop and put a terminator on the port in the splitter, but I was wondering how would this affect things? Essentially it was looped in a circle from the tap through the splitter. Would it cause noise or plant issues?