Yes, he was. I had to pull out my copy of the Warren Report I bought secondhand somewhere. Its a rare copy in that the cover is upside down for some reason. The people on the commission are separated on Page iii are separated into 3 groups:
At top are 7 principle members: Chief Justice Earl Warren, Senator Richard B Russell, Senator John Sherman Cooper, Rep Hale Boggs, Rep Gerald Ford, Allen Dulles and John McCoy.
Then there is J. Lee Rankin, General Counsel with 14 assistant counsel including Arlen Specter.
Then at bottom are 12 staffers. So maybe Ford means he is the last of the 7 main members charged with conducting the investigation.