Two things about Sawyer's flash sideways in "Recon" seem off after learning it's the afterlife.
First, Sawyer says his parents died when he was nine. His parents actually died when he was eight. This may seem like a minor continuity error, the sort that inevitably turns up in a series this long. The weird thing is, the show as recently as the season five finale correctly dated their death. With that date so fresh in the writers' minds, why would they get it wrong?
Second, Sawyer is still searching for the "real" Sawyer. Why? He resolved that long-standing issue in Season 3. He doesn't remember this, but why drag a resolved issue into the afterlife, and why should Lost return to an arc that had finished?
To answer this, take a look at the other person who's spending their afterlife thinking about Anthony Cooper. Locke doesn't imagine Cooper in a catatonic state because he wants quality time with him. Cooper instead personifies new baggage Locke accumulated during the series -- guilt over permanently injuring someone in a plane crash.
Sawyer similarly may not be still mourning his parents' death. Instead, he's seeking revenge for the death of someone who died later, someone who (sort of) died in 1977 instead of 1976. Someone whose death Sawyer was still mourning in real time when we saw that flash sideways.
Look at the next things Sawyer says when explaining his problem to Miles:
When I was nine years old...my father shot my mother, then he killed himself. Sawyer was the reason why. He was a grifter...con man. I've been hunting him down since the day I left the academy.
Which grifter named Sawyer do you think he's really trying to hunt down and kill?