Continuity mistake: When Hal is showing his friend how the ring works and has to "recharge" it, his grip on the lantern changes between shots. (01:09:45)
Continuity mistake: When Hal gives the present to his nephew, the stuff on the night table changes positions between shots.
Continuity mistake: When Hal swerves to avoid crashing against the car in front, the car disappears from the side view and later angles when he passes it.
Continuity mistake: When Hal visits his nephew, the pillow in the background changes positions between shots.
Continuity mistake: When the ring of Abin Sur chooses Hal and its beam of light takes him away, at the moment that Hal falls to the puddle, his body changes position between shots.
Continuity mistake: When Sinestro is talking to the Guardians for the first time in the movie, the last shot of him shows his scar on the wrong side of his face.
Continuity mistake: When Hal is with his nephew, several mistakes occur between shots. When he puts his arms around his nephew, in the first shot he puts his right hand on the boy's shoulder, but in the next it's his left hand that's on the shoulder, then he puts his right hand a second time on his nephew's shoulder. When he's leaning back on both his arms in one shot, in the next he's leaning on only his left arm and then puts his other arm behind him. And the shot where he gives his nephew the present, he suddenly has his right arm resting on his thighs.
Continuity mistake: When Hal is in the car wrapping up a box, the amount of paper by his right shoulder increases and decreases between shots.
Answer: In the comics Sinestro founded and led the Sinestro Corps, a group similar to the Green Lanterns, but they use the yellow part of the emotional spectrum: fear, rather the the green energy of willpower.