This should be considered while viewing finding paradise:
Something that coincidentally happens, that somehow enables the two doctors to finish their job successfully.
E.g. Neil running over the squirrel at the start of To the moon.
If the squirrel wasn't there for Neil to run over, the two doctors would have had no way of bridging Johnny's childhood memories. Johnny would have died without even remembering why he wanted to go to the moon.
But seriously. What are the chances of a squirrel coming out of nowhere right outside your next patient's property, just a few hours before you need it for fulfilling that very patient's wish?
If there DOES happen to be an event in Finding Paradise----a strange event, beyond the two doctors' abilities at the time----that helps them to fulfill an otherwise unfulfillable wish, this could mean that:
1. In the reality these patients died without their wishes fulfilled.
2. Someone is making these strange events happen through the memory altering machine, allowing the wishes of the patients to be fulfilled, to change a certain sad person's memories, so that he or she believes that their patients left the world "with a smile on their face in replace of a frown".
Or, I've had too much milk today and my brain is malfunctioning.