Not necessarily. It depends on the requirement. If I've completed or don't have any real work, but am expected to be around, then that's work. It's only if the second contract breaches the first or creates a conflict, and that's not inherent in time.
Edit: Misread your comment. If you're billing for specific and granular blocks of time, and doubling that up, then ya wage theft. But if you're doing that and also expected to be onsite anyway, then no not wage theft imo.
