It is a term of endearment used by on qualified football referee to describe another equally qualified referee but of whom it is believed has either interpreted and or enforced the known LOTG in a manner that is deemed to be below that of the required standard asn interepreted by the user.
This lower level of interpretation and or enforcement may be the result of inability, lack of understanding or due to wilful disregard for LOTG.
eg. a player wishes join a game of football, but it is noticed that they have a piece of jewllery that must be removed under the official interpretation of LOTG. One game, a referee allows the player to join in the game with or without correction to the jewlery. The next game another referee insists that the jewlery must be removed and refuses to allow the player to participate. An appeal against this decision may include reference to "but last weeks Ref.....".
Last weeks ref can usually be found with teams whos kit has obvious shortfalls, he may be wearing a bib in order to have a different colour to the team that have a "dark" coloured kit that clashes with the ref, he will almost never been seen at any form of mastermind group, association meeting or county cup appointment list. But he will be noticable by his audible quffing that every player loves him, always has great mach control, knows which of the laws really are important and by his fantastically low, if not absent, card count for either season on career.
Signs that you are inflicted with early stages of LWR may incude flippancy, lazyness and a drop in CFA involvement.
There is a train of thought that LWR should actively be outed and shot on sight as there is no known cure.