I had to go home for work during a trip myself and DH had back in August. Here is what I did. (This is all assuming that the person going home will not need to take any luggage home with him.) All I had was my Blackberry and my wallet.
Upon arrival at MCO, I went to the Mears desk and purchased a 1-way Mears ticket from the Dolphin back to MCO. $20.00. Then we boarded our DME bus to our resort. The night before I was to go home, I called Mears, told them my flight number, and received a pickup time. If you don't mind paying cash for the Mears ride, then you can just call Mears the night before you wish to go back, then they will schedule you a ride from the Dolphin, Swan, or Shades of Green, and you can pay the driver cash. I wanted to use a credit card, so I purchased the ticket in advance at the airport.
Then for our touring on my departure day, we were at the Studios. I then strolled over to the Dolphin, boarded the Mears bus, and was delivered to the airport.
I returned home, took care of my work, then flew back to MCO a couple of days later. I walked all the way down to the DME area and went to the Mears desk that is right next to the DME desk and purchased a 1-way ticket to my Disney resort. $20.00. I was then allowed to board a DME bus. (If you don't have a prearranged DME reservation, then you can purchase a Mears ticket to a Disney resort. You cannot arrange this in advance.)
At the end of our trip, we both took our prescheduled DME bus back to MCO.
If the person who is going home for a couple of days wants to bring a carryon or any checked luggage, then they will have to carry it onto the Mears van from the Dolphin, and check it themselves at the airport. If they check any luggage on the return trip, they will need to get it from baggage claim themselves.