After the dog returns, Paul asks Travis about any physical contact he had with Andrew. Despite clearly recognising the risk from touch, and ordering Travis and Sarah to 'wash up' and quarantine themselves, he wipes his own hands repeatedly over his face and beard.
On more than one occasion in the film, a lead character uses gasoline as fuel to start a fire, but then carelessly leaves the gas can in dangerously close proximity to the open flames as he lights his matches and starts the fire. In real life it would have been extremely likely that fumes from the gas can would have ignited, being so close to the open flames, and possibly caused serious injury or death to the lead character or others nearby.
The pickup truck used in the film initially has the branding on the front grille worn away/blacked out. But when Paul later returns to his house with Will's family, the grille badge has mysteriously returned.