Here's a good breakdown of the incident in this blog post.
https://medium.com/@cargun/radar-images-...1e3f516b54
Youtube videos showing the radio communications
and the AIS display of the incident.
If you can't be bothered to read the article
Tanker heading northbound spots target on radar
Calls Vessel Traffic Service (VTS), they don't have a clue whats going on.
Navy ship seems to have some stealth navigation turned on, they're hard to spot on radar and have no Automatic Identificaton System Turned on.
Only when ship is around 1.2 km away does the VTS suggest it may be a navy ship
Tanker still doesn't know that it is a navy ship
Tanker calls the navy ship on the radio they make contact and the tanker requests that the navy ship alter course to starboard(right)
As it looks like a head on situation in a normal situation both ships should alter course to starboard(right) and pass on the port side (left) of each other
But it looks like there is a ship on the tankers starboard side so they can't alter
Author suggests that if the navy ship could easily have altered course 5-7 degrees
The navy ship still doing nothing tanker is screaming over the radio for them to alter course
Collision Occurs
The tanker calls the VTS saying they hit something and say 'it could be a warship'
The VTS communicates with both ships
The Navy ship contacts VTS saying they hit something (4.5 minutes after the collision)
The author then said it could be possible the navy ship turned to port instead of starboard as the damage to the navy ship is on its starboard side
Conclusion - Based on this it looks pretty bad for the navy ship, not turning on AIS (during the incident) and possibly putting on some stealth navigation thing (hadn't they finished the exercise), not reporting to VTS, then not taking effective action when there was a risk of collision.
Also it how many people would have been on the bridge of the navy ship, on the tanker there could have only been 2 people maybe an officer and an AB, but the captain would of probably been called at some point