I have seen that approach used with safety programs in the oil field (only it is more of an after Accident review), with huge success in preventing future accidents. It is a lot safer out here than it was 20 years ago.
Funny, but so many people are conditioned to the blame game, any 10 people off the street involved in any incident will be playing CYA and blame shifting almost immediately. I have seen this in recent clips from NOLA.
It is tough enough to sit down with even industry professionals at the field level who have been assured that this is not a witch hunt to do a review of events leading to any incident, great or small, in an apolitical setting.
I really have trouble envisioning politicians being capable of doing this. The odd statesman might be capable, but on balance Congress cannot.
Certain members of Congress, however, are highly motivated by partisan political concerns to "do something" to give the appearance of "caring" in a non-election year so they can point back at it next cycle.
I seriously hope they will back off while the people who are handling the problems handle them, rather than disrupting the relief effort with this crap.
Unfortunately, just the opposite of what you hope to see is happening. Sen.s Pelosi and Reid today being just two of the more vocal examples. Pelosi has no idea what happened in or around the effected areas, but she's got some great suggestions on how to 'fix' things she doesn't even know are broken.