I played it various ways out of curiosity, shoot them, don't shoot them, try and get away, shoot your gang, etc.
Every attempt pretty much confirmed my initial suspicion the level was badly executed and placed in a narrative sense.
IW are great at action set pieces and online, but they sure suck at narrative and always have really - and I wish they'd stop these 'experiments' and just accept the fact.
Try to be reasonable... its easier than you think...