I liked the part about how they never actually found a drone at Gatwick, but "experts" (?) say there "probably" was one. I'm curious what they're basing that o

I liked the part about how they never actually found a drone at Gatwick, but "experts" (?) say there "probably" was one. I'm curious what they're basing that on, and who's considered an expert on phantom drones (as opposed to Phantom drones).