Hal Jordan mentions Gotham’s Bat-Signal because Guy’s green beacon copies Batman’s warning light, confirming the Dark Knight’s public presence in the DCU.
DCU
Why Did Sinestro Break Out of Prison in Lanterns and What Does It Mean for the Final Two Episodes?
Sinestro’s prison escape remains unexplained in Lanterns Episode 6, but it links Hal Jordan’s murder to a threat beyond Rushville before the finale.
Lanterns Episode 6 Theory: Who Killed Hal Jordan and Which Clues Point Beyond Rushville?
Lanterns Episode 6 does not reveal Hal Jordan’s killer, but Sinestro’s escape, the Halogram and a suspicious timeline point beyond Rushville.