This will be my last tout of Aspen/Atlantic Ideas Festival sessions. The video is not yet up on the main Aspen archive site, here, but please check in a few days to see if they've posted a July 9 session called "How Will We Drill for Oil?" The main presenter was Joe Leimkuhler of Shell.

The obvious caveats: Shell was a sponsor/underwriter of this conference and is an Atlantic advertiser. Shell of course has every interest in distinguishing its drilling practices from those of BP, as part of its case that deepwater drilling its not inherently dangerous and should continue -- as Shell has said it intends to do. (When asked directly about the now-disputed moratorium on offshore drilling, Leimkuhler said: After a 737 airplane crashes, sometimes you ground all 737s until you are sure what went wrong. But you don't necessarily ground all 747s too.)

With that noted, the presentation was different from anything I had seen before, in laying out step-by-step the differences in how you could design a deepwater well, with multiple, redundant fail-safe points and blowout-prevention systems (which is what Shell says it does), and how, according to Leimkuhler, BP did design and drill the well that has so catastrophically failed in the Gulf. On one side of his chart, Leimkuhler showed the multiple check points and controls on one of his wells; on the other side, the BP well with most of those controls and fail-safe points omitted.

A recent industry-news story quoted Shell's chief executive Peter Voser thus: "Voser said Shell would not have drilled the [BP] Macondo well in the Gulf of Mexico in the same way as BP did. But he did not elaborate." While Leimkuhler was very careful to keep saying, "We have to wait until all the evidence is in" and not explicitly to blame BP, his charts provided the elaboration for the contrast.

Again as caveat: I can't independently vouch for Shell's presentation, and I don't know what BP would have said in response. I am not making a case about the drilling moratorium or saying that the Shell design is "safe." I am saying that at face value, this was a more easily-comprehensible -- and therefore infuriating -- indictment of the drilling practices behind the BP disaster than I have previously seen. I think that was the general crowd reaction too. (I discussed this briefly on Weekend All Things Considered, with guest host Lynn Neary, yesterday.)