After doing 4-3 accreditation last season, I was only able to observe on Wessex or Hellenic since I was still operating as an AR on the Western League. I was advised by the coordinator and both chaps I did my shadow observations with that this is generally accepted practice. Were I (or anyone still active) to be observing people with whom I'd worked recently or prospectively then it might be difficult to abide by the reporting principles contained in Section 2 of the Step 3-6 Observer Manual which quite clearly states:
Observers are encouraged to disregard any past experience or opinion (either of their own or those shared by other colleagues) regarding the match officials being observed. Performance must be judged solely on the game observed.
Conversely, were I a level 4 referee being observed by a person who only 2 weeks earlier had been running the line for me, I might find that rather odd.
Just saying like ....