The CM was not correct. My DH & I have done that tour. We entered through the International Gateway (boat entrance). FWIW, it opens at the same time as the main entrance. You and the rest of your family can enter EPCOT there at opening. You'll just walk through a portion of World Showcase to get to Future World. This is the entrance to EPCOT that all of those staying at the EPCOT resorts routinely use.
Be sure your DH allows enough time to walk to the tour meeting area. If he is supposed to be at the meeting place by 8:30, he'll need to be at the IG turnstiles no later than 8:10 or so. Even though the IG will not officially be open until 9, there will be CMs there. Your DH should just tell them that he has the Segway tour booked. They will scan his park admission ticket, & let him in (be sure he has the confirmation nunber. Normally the CMs at the entrances have a list, though). Then your DH can walk past England and Canada to the path to Future World and on to the meeting place.
We loved the tour - hope he does too.