Is your memory of something someone said twenty-some years ago trustworthy? That quote might have come from a journalist, but it isn't journalism.
Anyone's recollection after decades is untrustworthy. Memory is simply not very reliable.
Having the ability to observe the effect of one's lie on a nation-wide basis over the years, might result in having that memory sharpened and refined rather than dulled.
The one who needs to demonstrate a sharp memory (journalist) and the one who lied (Erlichmann) are not the same people.