That smells exactly like they knew he was on the bus, and needed a civilian to call in a tip to justify the huge response that magically showed up in the middle of nowhere in minutes.

Why wait for pretext if they wanted him? You're guessing he was already under surveillance. If "they" wanted him they would have grabbed him. There was a nationwide manhunt for him. "They" were desperate for any details. You're giving "them" too much credit. "They" clearly didn't have capability and capacity to find him without a rando calling in.