Exactly. I feel like it's not worth arguing with someone taking this dogmatic approach, but a company that really wants to be in litigation with you will do what it can to convince lawyers and judges (who don't really know how the details of technology work) that you still had access to things and could steal or change them.
A great example is not removing you from cloud services - this makes them look bad but also makes you look capable of theft. It's more important that it remain possible you committed theft than not. Another is if you used a personal computer for work, as most people I know in startups do these days. If they won't supervise a deletion of the code off your computer YOU CAN NOT DELETE IT! If you are sued, you've now deleted things - what if you turn out to be the only person who had it? That's the real theft, and this has come up in real life cases I've seen - it became critical that the code WASN'T deleted.
The statement to never leave with code, email accounts, etc. is just not practical. It requires cooperation from your employer that will not exist in a situation where they're planning to try to bury you in litigation. It's a fools errand to try to pretend like there are reasonable steps the defendants should have taken - they took many reasonable steps and the plaintiffs can always find more that should have been taken.