Theory: This is not Hal Jordan
I'm not against them snuffing him if it serves the plot well and provides meaningful character developments as well as explained sufficiently. But as a fan of twists, I would imagine it's not that simple. Especially since he will still appear on most if not all later episodes, making audience invest on a character that they knows how he'd end just doesn't really make senses.
In the earlier scenes, we know that there are more than a dozen (known) alien races that can change their appearances, even their biology enough to fool human's latest detection technologies. It's very probable that he used their technology to change a person (may be alien, may be another earth person) into his decoy, may be even changing his own, so he could freely doing some underground investigation or moves without alarming his enemies.
Edit: Source of the image is Lantern, Season 1 Episode 1 last scene.