The quoted link discusses backdooring js by writing legit code that turns malicious through minifier bugs.
The only way to be sure is not minifying the source.
The only way to be sure is not minifying the source.
It has the answer to your question. Namely, you can write bugs that are exploitable that aren't present in the original source, that only appear in the minified output. Which means that a) it is a whole lot harder for someone to find (especially if it's something that is "obviously" correct), and b) it's plausibly deniable.