This is incorrect, and why the recipe emphasizes a brine of 5% salt. Botulism cannot survive in saline conditions.

Lacto-fermentation is the oldest means of food preservation aside from cooking and drying. It is used throughout the world for preserving everything from sauerkraut to pickles to kimchi to capers to fish. The garlic and the capsaicin also have antimicrobial properties that prevent especially molds from growing, making this a very easy ferment.