DOC.400,
'1' and '2' are just poor procedure, but '3' and '4' are potential killers!
Why not just explain the danger to him?
If he's a friend, he probably won't mind discussing it. I have the same 'problems' with some people I fly with, but I always speak up. If I do something wrong, I always like someone to call my attention to it. (Of course,no one ever has to remind ME because I always fly exceptionally well!
)
How about adding something to the written checklist?