It should be noted that Warren had financial and business disagreements with Jeff, and those do tend to color his view of Jeff. Also, to be fair, Jeff is not the only one who Warren had those issues with, but he is of course dead, and unable to speak for himself. There is, or was, a lawsuit between Warren and Jeff's family as well.
What Warren once told me most aggravated him was an interview on the PBS program Nova, where he felt Jeff took too much credit for work he and Warren did together. One should note that those programs are often severely edited, and what Jeff said may have been edited out of context, and some of what he said may have been edited out completely.
Regarding Jeff's untimely death, and the circumstances that surrounded it, Warren had some very interesting things to say. He placed a lot of blame on the plane itself, and how it was modified. He did not agree with much of the FAA investigation, and much of what he said makes sense. Last I heard, Bruce Pruett, who owned the plane and decided on the modifications, was suing Erickson Sky Crane and Jack Erickson over the loss of the plane.
It is interesting to note that the plane was recovered mostly intact, one wing was cut away for the recovery, and it was stored mostly intact at an airport. A friend and former P-38 pilot, who corresponded with Jeff drove up to see it, but oddly enough, the plane was cut into very small pieces and sold for scrap, not salvage, but scrap. This was done, according to the airport personnel, within day after the wreck was inspected by the FAA and released. odd, from the FAA report and description, the plane was quite salvageable and repairable. Figure 16K pounds of mixed scrap, even mostly aluminum, would bring about $3K at best. I know of total wrecks that were sold for over $70K. Imagine the value, in the mid 1990's, of a mostly complete wrecked P-38.