Given the transmission is an omnidirectional signal of some power, it could be picked up with the right equipment. Although some forces encrypt their microwave downlinks, so it may not have been possible to make sense of the downlink. Many aircraft have the ability to turn this on and off, if they are covering others force areas or working on specific operations.
Did any of this footage get released for a news item at all? Although I would not be surprised if they did have a suitable receiver, it isn't rocket science if not encrypted.
Given what the press have been up to over the years, picking up the pics is quite mild. By hacked, I presume they believe it is quite a feat to be able to pick it up at all. NB: There would be be no audio, that would be on AirWave which is secure.