The gasps for air and wretching was not the alien, but Dr Jonathan Reed, like a guy passed out at a gym.
Why wouldn't a carbon based lifeform evolve lungs? Many claims have been made that ancients (prior civilization) live underground and in the ocean. US government coined the term "non human". Anomalous crafts and beings aren't necessarily out of this world.
While filming the his investigation of the being, there were a number of close ups. Just like in the 1996 Varginha case, the film is blurry.
The fake hovering craft by George Adamski was obvious. The landing struts were lightbulbs with the GE logo written on them.
But not everything is an obvious debunk. Take for example Bob Lazar with the disinformation campaign against him, and the evidence that surfaced decades later that has vindicated him.