Duncan’s flight went from Belgium to Dallas.
He connected through Dulles, although that didn’t matter one bit.
They wouldn’t have detected anything at all.
The way I read the new rules, Duncan’s travel would have been considered to have originated in West Africa. So under the new rules, he would have been required to be screened at Dulles.
“Duncan’s flight went from Belgium to Dallas.”
No, it wasn’t. He went from Belgium to Dulles and then Dulles to Dallas.