What he did was nothing more than an ignorant and baseless jab at a US ally at the expense of truth and logical thinking. He is ignorant in that a 'certification' is not a 'law'. A certification is a declaration that something is good enough to do this or that based upon reasons A through Z. It has no enforcement other than through persuasion.
It is up to the government to make legal enforcement based upon this certification, not the engineers who established the reasons A-Z.
If South Korea had only
copied the FAA standards and called it South Korea's own it would have made no difference. He would have taken the same jab from a different direction. The irony here is that the Chinese probably did exactly just that but never made public about it.