Advice needed after problems arose during new liner install.

I Have a 16x32 IG pool built in 1984. It has steel walls and a vermiculite base. I needed a new liner so a local pool contractor who has been in the business for 30 years came over and measured for the new one. The day came to install it and when they pulled the old liner there was a 2” crack about 10’ centered in the safety ledge of the diving board side. He said he needed to fill with vermiculite and that’s what he proceeded to do. It took him about ten minutes to fill in the crack, and he was being very careful because he said he didn’t want the wall to fall in. Then the new liner was installed and filled with water after being filled the pressure pushed in a big area about 5 ‘ long and 1’ tall in the sloped section .
It basically looks like a 5’ foot tall person was picked up horizontally and thrown against it leaving a big dent. The pool contractor said that there is nothing he can do. He doesn’t deal with vermiculite and I would need to get someone else to fix it. He claims he is not liable for anything because water had washed out the sand behind the vermiculite base. I feel like when he saw the crack if he was not experienced with this he needed say “ alright this needs to be fixed but I can’t do it, we should get an expert over here to assess the situation before the liner is installed and $700.00 worth of water put into it. Also if the wall was coming up maybe he should not have put the vermiculite patch in there because now its holding the top part out and it can’t settle back in. I don’t know. I am no expert. I did speak with another pool professional that builds and installs pools and he said if he sees any cracks or anything in a vermiculite base when he is installing a new liner in an older pool he will take a sledge to them and find all the soft spots and repair them as needed before he installs the liner.
My question is: Is the contractor who installed the pool liable for anything in this situation? or is it an “ act of nature”. He charged 2200 to replace the liner and I’m guessing he made about $1700 profit in less than six hours time. It took him 2.5 hours to install, 1 hour to measure, and im figuring time for him to order the liner. He had 2 guys with him during the install for 2.5 hours but they didn’t know what they were doing and he was probably paying them $8/hr.
If I was him I wouldn’t feel comfortable making my normal profit that I make on every pool if this happened to my customer. Should he at least give back some of his profit? To go towards fixing the pool, which includes draining it, pulling the liner back and having a pool builder rebuild the wall for $2000.
Any input on my situation is greatly appreciated.
Thank you

Can anybody help?

This certainly is a grey area. Do you think that he should have seen the problem with the pool? If the sand was washed away behind the intact vermiculite it would see to be impossible to see without removing the vermiculite. Is it now causing a problem with the liner or is it cosmetic?