i am replacing an old light fitting with 4 downlights so i bought a quickwire switch and load fitting to accept the loop in and loop out and switch cables and then daisy chain the 4 lights out from the remaining load terminal in the qw. easy job im thinking but on taking the old light off to reveal the ceiling rose i am confronted by a wiring arrangement that doesn't add up.as you can see from the photo the loop in and out live and neutrals seem okay as does what appears to be the switch live (red wire) the mystery is the black wire on its own in the middle of the neutral terminal. this would logically be the other wire from the switch but surely that should go in the live terminal. all the lights work okay. can anyone shed any light on what this could be or how to proceed. thanks in advance