Who was in charge of that office? Lawrence Preston Geiss, better known as Jeff Bezos' maternal grandfather, who also worked for the Atomic Energy Commission.
The anomalous debris was then sent to New Mexico to be taken charge of by Lawrence Preston Geiss.
So given that Harold Malmgren was in charge of the nuclear test for the White House, he decided to scope things out with Lawrence Preston Geiss.
According to Malmgren, Geiss was directly involved in reverse engineering recovered craft in this exact period, so Malmgren went to go meet Geiss in New Mexico.
And according to Malmgren's tweets, Geiss was directly involved in reverse engineering recovered craft in this exact period.