If Penguin sees a link toxic link, it will apply a penalty based on your link profile. No human reviews this.

In addition to Penguin, Google has added more human resources to their spam team who can manually penalize sites which have toxic backlinks.

According to Search Engine Watch, Google initiates over 400,000 manual actions a month. 

Manual link reviews and penalties might be trigger by:

You can request reconsideration for manual penalties, but we’ll talk more about that later.

How to Determine if You Have Toxic Backlinks

There’s not much you can do about algorithmic link penalties, you just have to improve your site’s overall link profile.