Fridge / Dracula A.D. 1972

Fridge Brilliance

• The day after the ritual, Johnny tries to explain Laura's absence by claiming that she's gone to visit her parents in Ramsgate (in Kent, south of London). The rest of the gang aren't convinced, as they're pretty sure her parents actually live in Watford (in Hertfordshire, north of London). Given that it's stated elsewhere in the film that they've all been friends with Johnny for just a few months, it makes sense that he would not know much about their backgrounds — especially given that his main target is Jessica, on account of her being a Van Helsing, meaning he wouldn't be as interested in the others as he is in her.
• The fact that most of the gang do not seem to know where Johnny lives (when he takes Gaynor to his flat, she actually asks him if it's his place) also makes more sense when you consider that they've only been friends with him for a few months. And given his reasons for befriending them, he probably didn't want them to find out too much about him, lest they decide to distance themselves from him before he could suggest the satanic ritual.
• Bob does not last long after becoming a vampire; Johnny vampirises him in order to capture Jessica, and the next we see of him is when Van Helsing comes across his body in the churchyard. Unlike Johnny, who is descended from the Count's nineteenth-century servant, Bob probably has little or no knowledge of vampire lore, and so had not prepared a resting-place where he could hide during the day, thus rendering him fatally vulnerable to sunlight come the dawn. It's possible that Johnny, who only needed to have Bob on-side in order to capture Jessica, fully intended for him to be the vampire equivalent of a Red Shirt.