One of the things they did amazingly well was in giving the viewer that 'claustrophobic' feeling of what it would really be like.
When they were passing thru those tight spots I was squirming and flapping my arms to try and relieve my own claustrophobia. Yes, I do suffer from claustrophobia... not severely but I definitely get the sweats in tight spaces.
I know I could go cave exploring, (I've done it), as long as it's semi-open... room to move about even if limited. I can handle that... but put me in a chute where my arms and legs are severely confined and I think I'd snap.
Sidenote: the New Idria Mines are VERY near my ranch.... hundreds of miles dug into the mountains and long ago sealed off because of the danger. I have been in several of them, but long ago. I'm still tempted but not a chance in hell I would want to expose my grandkids to that... far too dangerous. - JamesJM