If SJ pushed Ives to iterate through 100s of designs, tweaked each one and then iterated again whose creative work would it be?
If SJ sat down and explained what he wanted in excruciating detail (given the stories of his attention to detail this is what I would expect), and through trial and error Ives arrived at what SJ wanted whose creative work would it be?
I think there is clearly no single creator in either case. Ives gets a lot of credit for being a great designer and being the one who helped SJ realize his computing vision. Given SJs OCD about details I don't think it was ever a case where he was playing golf, took an Ives design and just pushed it out as his own.