Yeah, yeah. I’m not saying it is easy business. What I am saying is that “bouncing around many companies in a quick succession and then leaving for their home country” is exactly the pattern one would exhibit with that plan. If one would want to show that their plan didn’t work out then one would be talking about other things. For example that they only got junior jobs with no access to the code/secrets, or that they were only hired in fields outside of their interest, etc etc.
I would be very careful doing that at Google. Even if just about anything is accessible, I imagine most access is logged. If you are downloading everything not related to your job it could raise some alarms!
Some repositories needed to do your work, sure. Not necessarily all, and the more interesting work may not be available to just anyone who joins.
If it's a company like Google, you may not even end up at the group you interviewed for.