There are animation studios that are dominated by producers and animation studios that are dominated by directors. It's true today and it was true in the past as well. Disney was a studio heavily dominated by the producer, Walt Disney. His presence in story meetings and approving all the steps of the process mean that nothing got on the screen without his okay. Directors, regardless of their own points of view, were there to serve Walt Disney.
As a result, we don't really have much of a handle on many of the Disney directors. Those we can take the best measure of are those who directed shorts after the features became Walt Disney's main interest. When his interest in shorts declined, it left openings for directors like Jack Kinney and Jack Hannah to express more of themselves in their work.
However, there are some directors who never got out from under Disney's shadow. What are we to make of them? Which brings us back to the whale chase in Pinocchio and the sequence director Bill Roberts.
Not a lot has been written about Roberts. Shamus Culhane probably wrote the most in Talking Animals and Other People. When Culhane started animating at Disney, he was assigned to do corrections for Roberts, who at the time was a Pluto animator. What we learn from Culhane was that Roberts wasn't very talkative, struggled with his drawing, disdained the cuteness creeping into Disney cartoons but was sincerely interested in the work that he and Culhane were putting on the screen. Jack Kinney, in Walt Disney and Assorted Other Characters, says that Roberts went into real estate and construction after Disney and reportedly became wealthy. Those comments are like bookends on Roberts' career, but the middle part (which is the most interesting) is a blank.
No doubt that the story sketches and the layout team under Al Zinnen contributed many ideas to the whale chase, but Roberts was the director. He's got to deserve some of the credit but how much? Roberts also directed the "Rite of Spring" segment of Fantasia, yet another action sequence with Woolie Reitherman animating, as well as "Mickey and the Beanstalk" in Fun and Fancy Free, another cartoon with a strong bent for adventure. Roberts sequence directed on Dumbo, Bambi, Saludos Amigos, and The Three Caballeros, but I have no idea which sequences he was responsible for.
While Alberto Becattini has Roberts working in the animation business as early as 1919, I have no idea when he was born or died. It appears that he left Disney in the late 1940's, but did he quit or was he caught in one of the post-war layoffs? By now, even his children (if he had any) may have passed on. So we've got a name and a few reminiscences, but no real way to judge a director who worked on some of the most important animated films in history.