Dear Annie: My take is that Welles and Houseman were tremendous collaborators, but like many collaborators, they got under each other's hides. Given tremendous pressure, much anxiety over the first film project, and apparently working, one way or another, 20 hours a day, Welles blew up at Houseman's questions about their direction, and insulted Houseman in front of the Mercury Players at Chasens, a public place, physically attacked him. Houseman never forgave him, and attempts at later reconciliations erupted in fresh arguments. Houseman had a legitimate desire, as did others, to be recognized for his contributions. [It should be noted, however, that they all colluded in the romantic notion that Welles did EVERYTHING, whereas he actually did maybe 80% of what he was credited with.
They were a great team, each giving what the other needed, to create unmatched quality, with verve and genius, going from strength to strength in several mediums, as long as they were together. Geraldine Fitzgerald, who knew them both well, said Welles was "like a busted water main," and that Welles needed Houseman to direct the flow of his talents. He was never so successful again, following the end of their partnership with Native Son, on Broadway. Houseman went on to show that he was very good with many theatrical, film and academic projects.
We can only speculate what might have been accomplished, if they had stayed together. Houseman was a man of great taste, judgment and business acumen.
I like his memoirs. He perhaps needed to escape Welles' charisma, in any case. The hurt was obviously very deep, on both sides.