If you really think you were drugged you don't change the story. Foreman has stated one thing than another over the years. I heard him on radio state he was not drugged and it was just him trying to justify the loss.
The story of him being drugged came out much later. Somewhat after the fight Foreman stated "The canvas was too soft, the ropes were too loose and the count was too fast." It was a good month or two afterwards that the headlines in the magazines said, "I was drugged." Again, a grain of salt here. The Jimmy Young fight was fought against the same style of fighter in the same heat and he was still found wanting. It was a stamina problem with Foreman clean and simple. If you didn't fall and got him in deep water, you had a real chance. It was his style. Like it was the style of Earnie Shavers, Alfonso Zamora, et al.
No I don't think George was doped but he does and its not the first time the subjects come up. I remember Jimmy-the cat-Dupree was the favorite against Vincente Rondon but came put barely able to stand and was taken out without showing anything, both totally against his history. In that one I sided with Jimmy believing he was slipped something while George was just in against someone better then him.