I thought it was strange that the one on the tripod watched him forever. And watched him take a shot and jumped back and let him get off a burst that killed one and put 2 in critical. Then takes his shot. My only guess is maybe they were afraid the guy was part of security, although I don’t know how they could think that after seeing him. The police knew he was up there also. For minutes. I figure maybe they were also checking with police and SS to see if it was one of there’s. They could have at least crawled up and looked.
The shooter was wearing cameo similar to what police might wear. They surely needed to be sure this wasn’t local law enforcement sniper before just blasting him.