Rabies infection is a slow process. It does not happen quickly as shown in this movie. In people, the incubation period (the time between initial contact with the virus and onset of the disease) generally ranges from two to eight weeks. In rare cases, it can vary from 10 days to 2 years.
When Rollo is about to stab Roger while he is on the table, right before Rollo raises the dagger, a crew member is visible in the far-back left of the house.
Back home after being dosed with LSD, Doc Banner is sitting at his kitchen table. As Sylvia says, "Come on, Grandpa," and helps him up, the moving shadow of the mike and boom is visible on the refrigerator and wall directly behind them, to the right of Sylvia's head.