Question about RRSP withholding tax

The withholding tax on RRSP withdrawals is just a sort of placeholder until tax time, right?

So two different examples. For the sake of simplicity for both examples let's assume the combined provincial and federal tax for me at 0-50k is 20%.

1. I make 30k gross in a year. On top of that I also withdrew 5k from my rrsp, they charged me the 10% withholding tax, so 500.

Time to file my taxes, I would now owe another 500 for the rrsp withdrawal, right? Because I should've actually been taxed 20% on that?

2. I make 10k gross, but withdraw 40k from my RRSP, they withhold 30% of that, so 12k.

Time to file taxes, I should expect a return of 4k because I should've actually been taxed 20% on that withdrawal, right?