I dont disagree with you that he could have actually made up stories rather than just forgetting/absent mindedly omitting information. However, do we really know exactly what he told LE or didn't tell LE? We know he admitted to lying but we don't really know how he phrased those lies and I do think that's somewhat relevant. It could be that he was deliberately deceiving them or it could be that he really just was so stressed at the time that he twisted his words around or mussed up the details inadvertently. To me, it's really hard for us to ascertain which actually happened since we don't know exactly how those conversations went (ie how the questions were worded, in what order they were asked, what JW's state of mind was at the time, how exactly he worded his responses...IMO all of those things could be telling but we just don't know)
If we can't believe anything the witnesses say, anything MSM says, anything suspects say and anything LE says, we might as well just fold up our tents and go home. In order to build a theory (or theories) we have to trust people are telling the story honestly to the best of their abilities. (That is why deliberately lying throws such a wrench in the works.). Some people in LE have lied and do lie, with horrendous consequences. But at this point, in this case, I don't have any reason to believe LE is doing anything other than recording what they have been told. I have thought from the beginning that the "JW lied" could have been LE's emphasis because they believed he was involved, rather than the more innocuous "made a mistake". (I like Facundo's skit - I imagined them verbally backing him into a corner as well. But why/how did they know he wasn't being truthful the first time?) It's interesting to me that both are in the doc, so LE made a distinction.
Omitting something because you "forgot" makes sense to me, especially in a stressful situation. Making up a story of how you did something is different to me. It would be like if I told LE that I was on the other side of the street or in a different lane when I was hit, or that I had the windshield wipers on because I had just used the washer fluid... There has to be some reason other than being flustered that someone would create a narrative rather than just say what happened.