The Last Slumber Party logistic quandry

In the [cough, cough] "classic" 1988 horror flick The Last Slumber Party, there are, shall we say, certain flaws. One just seemed to "take the cake" for me. After all the implausible and sometimes incoherent meanderings, towards the end of the flick, the dad walks back out to his car after returning home from work. It's at the 01:04:18 mark. He (presumably) was home from work, but got a phone call prompting him to return to work. When he walks to his car at the mentioned time, his car door is very obviously open. As the movie barely passes the 70 minute mark, it's not something they did to save time. Does anyone know of anyone leaving their car door open? It was a really really bad movie, but this seems even too obviously weird and stupid for even this movie. Does anyone know of any precedent for this? Even in West Coast culture?

This is another question, like my Twilight question, that is to be blamed on RiffTrax. I expect it's just stupidity and poor film-making, but maybe people do leave their car doors open. I've heard weirder...