Im not very up on Australian signaling so I assume the lower aspect on the Junction signal is a call on route indication and the upper a normal running signal.
if so the approaching train occupies the overlap track of his junction protecting signal this caused the green signal to revert back to red. Before that happened the camera train had a proceed signal into the passing loop and this would indicate that the points ( HW 2000 or 1000 machine by the looks of it) had detection.
So to me it appears that the approaching unit has past at least one signal at red possible two depending on the layout that is adopted in Australia for junction signaling. If it is normal to have an automatic warning system (I assume ATW is the same as our AWS) he would have had to acknowledged it at least twice or more likely 3 times so it appears from the film that the camera train had the road and route set correctly and the approaching train SPAD at least 1 possible 2 red signals.
If the system is SSI (solid state Interlocking) a simple tape download will reveal what happened.
As for the level Xing earlier in the sequence, why he passed the red signal beats me. If the Xing had failed it's normal to pass at extreme caution so why he went over at what looked like line speed I have no idea.