**not off topic**
I mean in that sense a lot of law enforcement on this server use helicopters to gain vantage points on accessable roofs during store robberies and Gun stores, its clearly seen that the roof can be accessed both inside and outside from the POVs provided.
1.18 It is forbidden to use places that cannot be accessed by foot or ladder when event already started and it is not allowed to use highground such as highways which are not accessible from inside the event once it has started. | Jail 120 min
You can see that the person uses the foot to go to that location, which shows that the roof is accessable from outside. And the roof is also accessable from inside. Hence there is no violation of the rule 1.18
POV of how it can be accessed from the
Inside:
POV
Another POV of how it can be accessed from the
Inside: POV2
POV of how it can be accessed from the
Outside: POV3
(Note: I dint aim down sights or use first person to get to that area. I purely used my foot to reach the area)
All 3 of these exhibits show that the area if accessable from
inside and
outside.
In reference to ER 1.18
1.18 It is forbidden to use places that cannot be accessed by foot or ladder when event already started and it is not allowed to use highground such as highways which are not accessible from inside the event once it has started. | Jail 120 min
Can be accessed from inside 
Can be accessed from outside 
Can be accessed by foot
Is not highground that is not accessable from inside