The guy isn’t cheating his company, he is competing with his company. If they make their employees sign non-competition agreements, then he is doing something that could get him fired. Such agreements, however, typically preclude employees from attempting to take clients with them after termination of employment (they often don’t even consider the possibility that someone might take a client during the course of employment). If the company was really careless enough to leave such a giant loophole in their contracts, it’s their own fault. If not, then I suppose this person’s actions could be considered unethical. I wouldn’t feel too bad for the company, though, given that this guy wouldn’t be making his offer if he had enough work in the first place.