Going back to this, since I'be bought the script I've done some more testing. I don't know if its my connection but the default sleep was too quick, the second pickpocket would never register. So I went up in intervals of 25ms until I was able to get 2 pickpockets, and I hit a point where I would occasionally get 2 but the second would be the "reaching" animation instead of the "bend down" thieving animation. I think this means that my second is happening after they've stood up, too late. I've been trying to find the balance where I could get 2 as intended but I think it just might be the method of the script itself.
Now this is just me, if it works for other people then go ahead. However, it's almost like I would need different sleep times. I think the first one needs to be shorter (much closer to when the knock-out animation occurs), that way I can have a longer sleep before the second pickpocket so that the click registers and voila a double pickpocket. In the current state I think having the same sleep makes it to where one is too short or the other is too long, I haven't been able to find a happy medium, but I'm trying!