The only humor that movie possessed was when MacCready turned around and saw Norris' severed head sitting in the doorway. He remarks "You gotta be f**king kidding!" ... or words to that effect - which was not only contextually appropriate but also a great tension reliever after we'd seen Norris chest abruptly burst open without warning and sever the doctor's arms with rows of shark like teeth embedded in its chest cavity. What a f*cking amazing scene!
It worked as humor because it was the most appropriate piece of dialogue at the tail end of a shocking scene where no other response would be adequate. Even then it's not LOL material, but rather a dark, stress relieving moment that is well placed in a movie that is otherwise on the edge of yer seat suspense. We're not laughing here because it's an intentionally funny gag - we laugh because we need to.
'The Thing' is a great movie for its overall lack of laughs and it's cold and uncompromising somber tone. It looks like 'ALIEN: Covenant' is definitely heading in this direction and it's welcome.