I think they mean during the same hours. So an 8 hour day is really 2-4 hour days.
Yep, I agree. And that *is* theft since both companies are paying the employee to work full-time for them.
That sort of thing has a tendency to eventually bite the perp in the ass.
When I was still in tech I had the chance to do a lot of interviews for job openings. Was surprised at what applicants thought they could dictate to their potential boss concerning the job. Also found a lot of fraud where a phone interview was demanded, and a "sleeper" did the interview for the applicant for a highly technical job. When "the applicant" showed up the first day, they didn't know how to power on their laptop, much less anything about the technology they were already supposed to have. By 10am they had disappeared, and was found 20 minutes later sleeping in a vacant office they found. That was an interesting an interesting day, as management walked them out the door by midday.
This is a big potential problem with “work from home”. No one can prove you are working in the manner you promised to work.