The VIPs had no reason to think the medical team would protect Ishtar! Or Kuzuryuu! If they're really racking their brains to come up with the way to go about this losing as few lives as possible, this isn't it! They didn't even have access to the information that those guys lacked buddies, either. Maybe Kuzuryuu let that slip to one of my friends or something, but Ishtar? He didn't have friends here, or time to tell anybody!

Somebody got a key from the detonator and thought that too. So even if the VIPs are completely forced by the worst kind of mind control to play this game with all their hearts - because we know for sure that in practice they're trying as hard as they can TO KILL US - somebody else wants to put more people in danger too!