There may be other things at play here. As a consultant myself, it can be tricky working with permanent staff at any given organization. Since there is no direct report link, we must find a way to get from them what we need to get the job done, without any official authority. Jacob may be inundated with work from his manager and asked to work with you on top of that. He may actually find himself in quite a bind.
Alejandro Diaz writes about culture, politics, and the workplace. His new business, D & E Management Solutions, Embraces Humanity at work https://dandems.com