I think it's more in Hill's head. He had quite a few INTs last year, and I don't think he wants to take the risks. The dump/dink throws are Hill checking down as he doesn't like what he sees.

It's him trusting the routes and the receivers. Like O'Korn on the TD past against Daniel...O'Korn threw it not knowing how the route would end up looking, but he trusted that it turn out as they had practiced.