It's a difference between saying "Joe come and look at this" and 'Joe looked at it and said "Cool"'
Hmm
In plainer terms, it's fine, to an extent, to have certain people in certain places so long as it does not impede whatever they may want to write for themselves (for example it would be fine to say I was in the warehouse, possibly fine to say examining crates because everyone was doing that, as I'd already said I was about to go in to the warehouse). What isn't ok is to actually write in certain actions for them and, even worse, dialogue (for example saying I examined some crates then went to someone else and asked them about the crates they were looking at after changing into a silk robe)