I actually agree with you that Zimbardo and Milgram are relevant to the wallet-steal trick. Keep in mind that the studies you are referencing didn't involve ran

I actually agree with you that Zimbardo and Milgram are relevant to the wallet-steal trick. Keep in mind that the studies you are referencing didn't involve random strangers being told what to do, they were people who had applied to take part in a study, were pre-screened and were being paid for their time. This is also how I suspect Brown's scenario played out, this man almost certainly went through a similar process and knew he was being filmed but was not acting according to a script.