Complete bunkum! It’s NOT a requirement, and if it is used to split someone apart then that guy wants to hang up his clip boardOk, so, I watch a new ref today and he is ok but shirt out
I watch a new ref tomorrow and he is also ok but shirt in
RA manager asks which one was better, I say "both same but ref 2 had shirt in" (as it was the only diff)
Guess who would be no1 and no2 in the RA managers mind...