I'm not exactly doubting you on this, but I am curious, how do you know?
I ask because watching it, it seemed like Dak sized up the field for a second, then reached over to nudge Zeke into his motion to the outside. Once Dak determined who was following the running back, from there he knew the way the rest of the coverage would shake out and knew Zeke would have a nice play based on that coverage. That, in my mind, speaks to Dak's film work.
Also, even if it was by design, you still have to appreciate the execution of it. It seems simple, but if it were, 2015 would have played out differently.