The radio station, according to the series, is located in the Flimm Building. When Les is on the ledge, the building shows a red brick facade. The actual Flimm Building is gray block with no ledges.
When Herb leans out the window and tells Les, "You know, I thought about it and it's okay if you're gay," the word "gay" doesn't match his lip movement. He actually said, "it's okay if you're a homo."
Just as Les is finishing up the phone call while out on the ledge, the boom mic is briefly visible at the top of the screen, then it's reflected in the window about Andy and Mr Carlson.