I think this was discussed in the League section...
When I played the first match in 4.0 league (having moved from 3.5), I was paired with a veteran 4.0 player and the first thing he told me was..
"Do NOT overrule me even if you think the call is different" .. I was SHOCKED
I stick to a simple rule... whoever is closer (now reading SystemicAnomaly
's post makes me wonder about this) will make the call, overrule if it's clear miss by my partner irrespective of the match situation and be ready to show the mark.
So when I play a league match especially with a new partner, I make sure to discuss this before match start.