But it's my theory the Dr. Edgemar scene was part of the "narrative" of the dream. He's supposed to not believe him, or his "wife", and shoot him.
At Rekall, McClane goes to great pains to describe how an implant is as real as real, that you won't know the difference. You even get souvenirs. How would Quaid go back to work the next week thinking it was in any way real if Mars now has an atmosphere and his wife is dead? ...I guess you could make the excuse that an "Ego Trip" package is not held up to the same selling points that a regular implant is. But again, that's an excuse outside of the film itself, like dreaming of Melina. Of course dreams aren't just populated with people you've met, but it's a curiosity that no one in the film itself gives a good excuse for the perfect-match Melina.
Here's another one: (me switching sides) Doug is already drugged when he sees "Melina" on the monitor, so you could argue that an implant works with the travellers mind to create a unique adventure, rather than a static set of faces/choices plugged into each customer. He sees Melina on the monitor because he's hazy and going under, and that helps cement her likeness as part of the final implant.