Truman Capote and Monty

I know Truman Capote insensitively outed Monty at a later date. Capote had been a dialogue writer for this beautiful little movie, when Clift still had his boyish good looks, as this was before both his terrible auto accident and the physical transformation that followed due to his drug abuse as well as that unfortunate car crash. Does anyone know exactly what their relationship, if any, was at the time of this movie? It's hard to forgive Capote for his mean-spirited revelations, and I was wondering if Capote's self-destructiveness, which he rebounded on his unfortunate victims had any grounds, particularly in treating innocent artists such as Monty in such a treasonous manner.