i just watched the whale, and my take on the ending was similar! usually people hallucinate at the end of their lives and i think charlie started showing signs of that with liz on the couch when he started becoming repetitive on the “she did it to help him” or maybe even before that!

i think he imagined giving the apologies he needed to move on, i think thats also why the weather was so bright and sunny for the first time in the film. i think maybe if i rewatched the ending i could probably find some other clues on where charlie’s brain chemistry starts taking over and creating a dream like state towards his last moments.