Definition of an "Instant"
Given that the commander is in charge, one of the challenges facing first officers flying with certain captains is being prompted to do something a nano-second prior to when said first officer was going to take said action.
I am not referring to safety critical items here but "housekeeping" items such as selecting the heading bug to runway QDM after VOR/LOC capture (for example). When operating we all have a certain mental sequence and sometimes one may appear to be a little "late" in making a selection but there may be a good reason for this.
I would be interested to hear other views but I feel that captains who unwittingly badger the FO to "hurry" non safety critical items can lead to a less that ideal atmosphere on the flight deck and is not good CRM.