Someone flew under the map with a deluxo or Opressor MK II parked it on the roof of the default Hangar under the map and shot you.
The Hangar interior is located under LSIA.
That’s where everyone’s hangar is actually located.
They did a glitch so that they could spawn the default Hangar and use their guns in it.
You may not have been able to see them.
Both of these scenarios have been a part of the game on and off for awhile.
Rockstar will usually patch it once they get a lot of reports that this is happening.
Your ability to bring the car underneath is no longer available. Ability to spawn underneath is still possible using job triggers, and spectate tricks. However any other wall breach method is not possible to get over to thedefault without the death barrier.
Since you have to keep God mode on when you're using director mode online, I'm not sure if they're able to bypass the death barrier using dmo