There was no mistake involved. No IRGC officer panicked. Iran deliberately targeted the Global Hawk after it failed to respond to hails to leave Iranian airspace and turned off its GPS, lights and digital systems.
It was acting as a hostile and Iran treated it as such. After sparing the Poseidon P-8 and its crew and passengers Iran shot down the drone.
https://straightlinelogic.com/2019/06/25/iran-message-sent-message-delivered-by-tom-luongo/