I am not saying it means it was an inside job. I am just saying it is a legitimate question. I am sure it is not easy to fully secure every possible threat scenario in an open space with thousands of people but seems like an obvious oversight for professionals to miss. There are a lot of people that aren't good at their jobs. I mean someone could have been assigned to it and he was talking to girls in the crowd or trading shitcoins on his phone instead and not paying attention.