I agree with Misnomer...the guy spent a year of his life passionately working on an Indiana Jones script, which he seems to think is as amazing an opportunity as any of us would. Then Lucas vetoes it (apparently with total stubbornness and no good explanation). The press asks him how he feels about that, and he tells them, and his feelings are totally understandable.
He seemed despondent at first, but he's moved on to "professional disappointment." Now he finds out his ideas are being used to a significant degree. In his own mind he's probably like, "Son of a *****, lord knows I don't want to deal with this, but I've gotta do what I've gotta do and try and get some credit for my ideas they pillaged."
I don't see anything wrong with it at all.