Tons of people saw the shooter on the roof, not just the BBC guy who got interviewed.If there was no one (CA team) supposed to be on that roof, then SS was paid to make sure no one was there. But what if two local officers were supposed to be there and were bribed to let this guy use their ladder/position. They may have 'confronted' him to throw investigators off the trail.
Imagine the scenario where a team was supposed to be there. It would explain the other teams hesitation to take him out. Especially if the two 'cops' were on the radio saying they were moving into position.
The one team on the roof that looked incompetent reminded me of someone startled or taking fire. Maybe they thought he was legit since they had obstructed view through the trees, and were genuinely shocked (came off the scope) when he started shooting?
Or was there a spotter on the ground shooting at them to buy him time?
I don't trust the guy saying he tried to warn SS. With snipers on other roofs, the only way he knew the shooter wasn't more security was if he knew what was about to happen. Check his background for antifa and or fbi ties and you'll find he was the ground spotter for the shooter.