[TeMPOraL]

Nowhere is this argument implying that regulation is bad. If those maintenance works are legal and the plane is still able to legally fly then it means that yes, somehow those non-US repair shops got the required resources to perform the necessary repairs with accordance to the standards and regulations.

[JupiterMoon]

Or rather no one has yet noticed whether or not the repairs are up to standard and because the US authorities can't inspect the facilities because they are abroad no one can know unless they are not up to standard and it leads to an incident.

NB I'm absolutely not implying that there is anything wrong with the maintenance. I'm implying that the US authorities would not know if there was.