Yes it is in Peter Wilson's book," More Ringside Seats", along with an interview with Rocky from his training camp about the KD,Rocky was as honest about it as you would expect.Its also in a Ring magazine ,feature on Hall, [Dec 2000], by Pete Ehrmann
I beleive he did ,of course they also fought and Simmons gave Rocky a scare, cutting his eye and making a stoppage a possibility,Marciano, in true fashion, turned up the heat and forced a tko in the 8th,but Simmons did not go down.