I have forgotten whose video it was but I saw someone pull it off and made it look sad easy.
It just took a coin and the audio device.
Dressed as the waiter you crouch behind the table the target is sitting at (near the railing side) and throw the device in-front of the guard. The guard will take the device and leave the target. Take a coin and toss it behind the target near the railing and just push the target over.
Silly easy-made me sad that is was kinda gamey. Nothing against the video creator just..both NPC's look and turn directly at 47 after both throws but still "forget"and reset themselves to pick up the object.
Not that I did any better. I just put a Galaxy S7 in front of his feet and walked away.
gamey as fuck