Teamwork.
They had a system. A team cohesion that flowed from years of working together.. Hand gestures, facial cues, each of them an integral part in how the team worked. They knew they could count on each other to have each others backs. They knew how the others thought. They knew each others strengths and how to work them to the teams advantage. There were days when they could preempt what the others thought, the conclusions they might reach over a piece of evidence, how they'd handle a suspect.
It was for this very reason that Beckett, Esposito and Castle shared a look; a wordless thought. This was about to be a very awkward conversation. So they were gonna leave it for Ryan to deal with.