What Is the Army Corps of Engineers trying to hide?

I read a troubling editorial, in the Times Picayune, today regarding allegations against the Army Corps of Engineers. According to the article:

Raymond Seed, a civil engineering professor at University of California-Berkeley, has filed an ethics complaint with the engineering society saying that its leaders and the corps tried to prevent independent teams such as his from gathering critical evidence at the levee failure sites and from speaking out about their findings.

Mr. Seed went on to say that:

1. The corps used its leverage with the group to try to silence differing views.

2. At the corps' request, the engineering trade group appointed an external review panel to provide expert advice to corps investigators who served on the Interagency Performance Evaluation Task Force, known as IPET. The corps paid the group $2 million for that work, a payment Mr. Seed contends is a conflict of interest.

3. The corps reneged on a promise to give his team access to soil samples at the 17th Street Canal and then tried to prevent his team from collecting its own samples. The corps only gave in after another independent research group, Team Louisiana, got the help of Louisiana's attorney general.

4. ASCE officials tried to keep their own review team members, as well as Mr. Seed's group and Team Louisiana, from testifying about their initial findings before Congress.

What is the Army Corp of engineers trying to hide? What role did they play in the levees' failure? We should all take Mr. Seed's complaints seriously and not remain quiet on this issue.