That sounds real nice. Makes a nice sound bit. But the reality is that it was impossible for every commissioner to participate personally in every witness interview, and to read personally every relevant piece of paper. You can stamp your feet all you want, and say that's not how things "should" be, and that they're paid to know everything. But that's how things are. They had to delegate.
The real question is who made the decision not to pass this information on to the Commissioners, and why. And perhaps whether or not any of the Commissioners were told of this, but failed to pass it on to the others. Those are legit questions.