It didn't say "the planner", it said a planner. They would hone the satellites into the bomber/s and backtrack steps which would have led them to a planner. They have surveillence drones flying around keeping watch of the air space for arrivals and departures at Kabul. Could have got a line on the bomber/s from any of those.
The United States conducted an airstrike against a Daesh-K*planner
