Some lawyers may have had a talk with Howard. The reason Indemand didn't want its HowardTV people in was because of liability. If a worker gets injured during transit to work = millions in damages.
BTW. Howard isn't the boss over one single person. He have no right to demand that they are in. Sirius XM pays their salaries. SiriusXM have to pay if someone gets injured. The only reason why they did the show was that Howard was lazy. Howard didn't want to switch day of the show. He could legally have done thursday or friday instead.