The opening shot in the Bellero house, showing Richard operating the laser while Richard, Sr. drinks a glass of wine, is repeated a few shots later.
A laser beam travels at the speed of light; so, when fired from a weapon, the beam should hit its target instantly rather than appearing to move.
At 36 minutes, the chamber effect that makes Judith's voice sound as if it's in a cavern isn't shut off fast enough to avoid affecting the subsequent voice of Richard Sr. The same problem occurs at 47:10 when the shield is shut off and Judith's voice can still be heard in a cavernous condition for three seconds.
The platform used to lower the alien being down the laser beam is faintly visible.