So what's with ...

... the CEO of BP being 'interrogated' by, what is that? Congress?

Guilty or not, shouldn't (as he says) "We wait until the investigation is complete"

Congressional hearing was basically a bunch of grandstanding by politicians because the CEO of BP makes a convenient whipping boy.  They can look like they are "sticking up for the little guy".

In reality, the CEO of a company like BP knows nothing of engineering or drilling, and is not involved in the minute day-to-day operations.  So when he says "I don't know", he is probably telling the truth.

Also, people are upset because BP hasn't fired anyone yet.  Firing somebody before an investigation is finished is like throwing somebody in jail before the trial is over...

Not to mention that Congress has no sense of business or risk management principals...  Cutting costs on something doesn't necessarily mean that it is less safe, and adding more valves, ect. wouldn't necessarily have stopped this accident from happening.  Congress expects businesses to just do whatever is the most expensive.