Hiding and disposability give it a kind of saturday night special quality, maybe better to just have it mounted in plane view. otherwise Every helicopter including those that don't have them could be seen as a threat, thus a target. It could put them in danger.

Hiding the cannon inside will give a short-term tactical surprise. When it's no longer a surprise, a fake cannon on the outside will do the trick.

Hopefully production models will have thermite destruction packs on the hardware. Jettisoning something like that could be like Christmas morning for someone who can rebuild a jettisoned weapon.
@SuperFool
Every helicopter in a combat zone is a target whether or not it has visible armament. This just allows unarmed helicopters to make some types of runs without an escort. While it wouldn't be good to take it into a known hot landing zone, it'd be enough for extracting people or leaving supplies when there's a chance of hostiles around.

What if the robot weapon accidently kills a bunch of kids playing "army' using their Gi Joe toy weapons.... Robot weapons are too risky !

I like the idea of a very tiny quad copter with a deadly accurate, small, single shot, rifle. If it is small and electrically powered it could get above an enemy and put a round right in his ear. Terrorists in a camp at night might find it quite unpleasant not knowing if their heads will explode in the night.

If their gunfire detection technology is any good, it could certainly be incorporated into other systems that give the pilots & crew immediate location of threat awareness. As for this system, "...allows utility helicopters to fly into hostile territory without an armed escort." Almost every mission flown is a utility helicopter in hostile territory without armed escort!
I understand this is the 1.0 version and perhaps as good a starting point as any but it does have a long way to go before it more realistically meets needs.
No structural changes needed is a running joke. It should say no structural modifications needed if you don't mind plenty of cracks. I don't recall many weapons mounted that didn't manifest the added stress in the form of airframe cracks.
I guess the helicopters won't have sling load capability because the mounting plate appears to cover the sling load hook.
You won't be landing with it in the operable position without crunching the device and a goodly chunk of the airframe.
I'll keep two crew chief gunners with electric mini-guns firing 2000-4000 per minute, aided by a screen displaying gunfire points of origin. They can assist the team being moved as well as deal with hot situations and gun feeding problems as well as get me in and out of tight spots by clearing the periphery.
Honorable mention to Duke. I hope they can use some of their tech for different systems that are still needed. We've come a long way but I sure would like a low level obstacle detection system for towers, poles, wires, birds, etc... and improved gunfire detection.

"360-degree firing capability."
Wonderful. Now it can also kill the soldiers and the pilot on board !

"power, communications, and ammunition remain inside the helicopter and feed to the gun"
How? for a gun claiming 360 degree firing, that will require cutting a very large hole through the floor. has anybody thought about this?
In the event of the system taking damage, where it cannot be either retracted or jettisoned, how do they solve the problem of landing?

@ toolman65 For planes that don't come with a hatch in the belly you could lean it far enough out the door that it can shoot under the fuselage.
Please explain the damage that keeps it from being jettisoned that leaves the airframe in repairable condition? Land over a hole in the ground.

Someone asked Benjamin Franklin what use there was for the Montgolifier brothers hot air balloon, to which Ben replied 'What use is a new-born baby ?'
This baby is already dangerous, and with the right target designation and detection capabilities it will be fearfully lethal - 'Airwolf' brought into the real world.
Mount one on a Snark and use it to terrify the terrorists.