It had a name. Kathlogroh. The little boy told them the name, told them it was a he, that he was friendly.
On closer inspection: they should have known he was no monster: he wore clothes, had tools attached to the clothes. He was injured, though not severely. He could talk after a fashion, in single words, in simple concepts. Not learned from the boy. Maybe he’d been monitoring communications before crashing.
He agreed to come back to the army base; he wanted electronics to build a transmitter. And: "Stay away crash. Invisible death." We’re assuming he means the radiation.