he take the tube right out of my hands

Dunban has seen Machina before - quite a number of them, in the Hidden Village, and so his experience is not drawn solely from Egil and Vanea and Miqol, the grand trinity of the last remains of the race on Mechonis. He knows that they are statuesque and stunning, highly intelligent and exceedingly gentle; generally striking, for humanoid lifeforms.

(He has seen High Entia in great numbers, too, and found conclusions much the same.)

None of this experiential knowledge, however, could prepare him to actually converse with Radzam, and avoid quivering in quasi-dignified awe under the researcher's sublimely benevolent shielded gaze.