And the bug wasn't really obvious, although the lack of input sanitation is something an auditor (given enough time) would probably point out.
Regardless, this quote from your link stands out: “it should never be expected that 100% of the deployed code has been formally audited.”
The audits of this protocol is also continuous.
Also, they specifically state that not everything is audited? Nowhere do they mention continuous audits.
Uniswap: https://uniswap.org/audit.html
Sushi Swap: https://github.com/peckshield/publications/blob/master/audit...
Alpaca Finance (high complexity in my opinion): https://docs.alpacafinance.org/transparency
A lot of projects provide their source and you can verify that what you're interacting with matches the source.