I know what you mean. The two DEK examples that I can think of in weighing the script differences is The Practice vs. Boston Legal (and then I feel he repeated himself with Harry's Law, and I won't even go into *that*). The former is legal drama while the latter is very much legal dramedy. So I accept that DEK can easily master both. But you can't do both in one show without giving the audience whiplash, so I'm assuming that with this subject matter being so grave, he's going to go The Practice-style route. And I'm very happy with that, since we need grittier medical dramas that don't trivialize the patient in favor of how the doctors get along.
I think the comedic restraint shown in the Sydney Plot C was something pilot-driven. The pilot has to set the tone for the show. I'm sure we'll get to see more of his sense of humor as we go along, but it would be appropriate if it was black comedy instead of the usual whip-smart banter you expect from DEK. What's awesome is that he's listening to the consultants re medicine so that his style (because he's a lawyer by trade) doesn't overwhelm the material. It's like having John Wells try to do a legal drama. DEK might be a little outside his comfort zone, so I give him some slack.
And to be honest, the Sydney subplot was really the weakest of the storylines. I wish they had concentrated more on what she was doing to arrive at the diagnosis (and thus cement her capabilities by showing, not telling) instead of having her run around like Chicken Little being made fun of by her colleagues. I know he did it to lighten the mood, but there's got to be a better way to do it than that. I think that's my only real script criticism for the pilot. YMMV and I might have to go watch it again to make sure. Too distracted by the awesome differences in this med drama and others to nitpick just yet. :)