I don't understand the ending...(spoilers)

At the end of the film, Cushing sees the creature for the first time, but then we suddenly see him outside, frozen from the cold.

What happened? My roommate thinks that Cushing imagined the creature, because he so badly wanted to find him. And that he was never in the cave with the thing, but actually freezing to death out in the cold, hallucinating.

But there were witnesses to the murdered creature, plus footprints and eyewitness to the hand in the tent.

Then the old man in the temple says that there is no Yeti, and I could not tell if he was serious or what.

I really liked this movie, but now I am not sure of the ending.

https://witnessmyrage.com/