Obviously it's no one's fault. We should just accept things the way they are and change nothing.
I'm not saying that, you'd want to find out why the warrant was high risk or deserved a SWAT response. Someone made that call, and it may not have been SWAT themselves. And you should take actions to ensure it doesn't happen again and hold them accountable. If you find abuse of power, you need to get rid of that person.
The key theme here is that you usually don't get all of the details about why things happened. Sometimes it's honest mistakes. Sometimes it's abuse of power. Sometimes there's miscommunication.