[what]

> If the pilot is making an error, the air traffic controller gets on the radio to tell them they're getting too close to another aircraft, in time for them to course correct.

They did.

Pretty sure military aircraft just don’t have to listen to them.

[AnthonyMouse]

They did after it was too late, because the crash happened. Unless the crash was intentional (and I'm not aware of any evidence of that), getting the warning sooner could have given the pilot more time to correct.