So why retract it? Got scared?
Could be. He was 18 when he made those videos which makes him about 24 now. Not hard to intimidate a kid like that.
Ask yourself this; he went to a lot of trouble to go into extensive detail in his first video. The next three were all done as responses to technical criticisms of each previous video and he went into great detail in each of those to demonstrate how he was right and they were wrong.
If he decided his original work was flawed why wouldn’t he make a video showing step by step how he had been in error? Instead he just puts up a comment saying he retracts?
His original work stands on its own IMO. What do you think of it?