Glencore walk away? From what? There’s nothing that they need to walk away from. They are not involved for the umpteenth time. They just fancy buying some goods, eventually.
Mainstay, Glencore don’t care, nor need to do anything - all they did was issue a note saying hey, we’re interested in buying your stuff if you can get it out of the ground in enough quantity and timescale.
These LOIs are just that, notes of interest. Nothing more. No funding attached. They are ten a penny on AIM.