Well… sure you could kill someone with a bottle of iced tea. But is it likely? I mean, you could kill someone with almost anything if you have the time and the willpower. You could force-feed someone a bag of circus peanuts until they suffocated. George Carlin once joked that you could probably beat a guy to death with the Sunday edition of the New York Times if you really put your mind to it.
But was the iced tea an imminent threat? The kind that required a response of deadly force? According to this dude, absolutely.