No, SDFM is not Kawamori's baby...the story was collaborative. Certainly, as director, Noburo ishiguro should get the lion's share of the credit.
Still, my instinct tells me that Ishiguro, the respected veteran, was really present more to keep the young turks in line and make sure they actually got the episodes done, than to do any real directing. I have no proof for that, however....and listening to Ishiguro's "guest appearance" on the Miss D.J. album, I'm not so sure anymore...