In the first case you still have a contract, and therefore contact law in your country applies. Blatent breach like "they wrote code that stole all our SSH private keys and then they deployed cryptocoin mining software to our systems" would be covered, regardless of how bad the contract is.

Same with hiring, the person may or may not be able to code, but active malice would likely result in firing, and the code they write should be subject to review before being put into production.

Of course you can argue "hey where I work hiring is trash, we write bad contracts and have no internal standards, so this 3rd party stuff isn't much worse" but I'd suggest that's not an argument most companies would make publicly about their processes.