Firstly let me point out that this response is neither intended as a defence of MongoDB defaults which are atrocious, or of the company, who are arguably duplicitous.
However I can _quite easily_ see how a non-native English speaker could use the phrase “if you know what you are doing” to mean “if you are careful”.
However I can _quite easily_ see how a non-native English speaker could use the phrase “if you know what you are doing” to mean “if you are careful”.