As this is a Headscratchers page, spoilers will be left unmarked. You Have Been Warned!
How were Xia and her goons planning to unlock the tablet if they had succeeded in their first attempt to steal it? From what we see, the tablet only opens when it has Will in front of it by scanning his face, so even if they had stolen it the first time during the whole satchel-snatching scenario that Ben set up, they wouldn't have been able to use it, because Will wouldn't have been around for them to scan him.
From what we saw, they may not have known exactly how the tablet was going to be secured; Ben would have had limited opportunity to update them once Will received the tablet, so they likely grabbed it on the assumption that it would just be protected by a more standard pass-code that Ben could get out of Will later at some point.
Why didn't Botha just ask Xia to reactivate the fire suppression systems so they could open the door? It's shown that the tablet can do that easily and Will says that it would open the door if the fire alarms went off. They could have grabbed the hard drive and left before the police got to them especially since the elevator broke.
What the hell was up with that hard drive? Zhang states that he got all the bad guys' data by "adding tracking software to the wire transfers". First off, that's not how a wire transfer works. But whatever, fine, let's say he just hacked their systems somehow. He gets all their most precious data (real names and offshore accounts) and uses it to threaten them, so they can't extort money from him in the future. Doesn't he know that this will immediately make him a target? Surely they'll be worried that he'll grow a conscience and turn them over to the authorities, so they have to take him down right now just in case. In fact, he ought to go on the offensive and leak the data now in hopes of getting them all arrested before they have a chance to kill him! Then he says that, if they kill him, copies of the data will be leaked the cops or whoever. Ok, so he's got a deadman's switch system; maybe he's set up some servers so that he has to check in once a day with a passcode and if he doesn't then the data goes public automatically. Fine. But then he says that, if they get the original copy of the data, they'll be able to reverse-engineer the tracking software and conceal their identities again. What? How would getting a copy of the data do anything at all to disable the dead-man's switch system? The whole point of a dead-man's switch is that it goes off regardless of what happens to you and regardless of how much of your stuff gets stolen. It's like he set up this entire thing with the specific purpose of building an Action Movie McGuffin.
There was something about the original data being needed to "prove" the crimes. So while Zhang could leak a copy of the data to the police, he needed to hand over the original to get them busted. This may work with a hand-written accounting leger, but this is not how digital information works.
