When Hank removes Frannie from Ray's room, Ray puts on a robe, and he is not wearing any underwear. However, after Ray yells at Hank from the balcony, his robe falls open, and he is shown wearing jockey shorts.
Though shot inside a sound stage, the opening shot of the front of the Fremont shows a completely wet street. Though done for lighting effect, nonetheless Las Vegas gets less than five or so inches of rain a year and the rainfall that does manage to hit the ground, evaporates almost immediately.
When Hank is walking in the rain to the house, the rain abruptly cuts off prematurely before he gets in the house. You can see where the rain machine ends when Hank is standing halfway under the rain with only sky above him. It has the effect of showing rain right next to him but he's not getting wet.
In the last scene, when Frannie returns home, you can see the camera rails covered with the carpet of the living room making two lumps that Frannie has to overcome by raising her feet to approach Hank when the traveling begins.
The ceiling of the sound stage is visible in long shots of the Las Vegas strip.