A branch impales Troy through his left shoulder. Madison pulls it out and Troy does not bleed out. Afterward, Troy is able to use both arms to bury his wife.
Throughout the franchise (The Walking Dead and Fear The Walking Dead), the dead have followed/chased what ever caught their visual attention. When Tracy leaves Troy, she darts between several dead, who all turn towards her, then turn away from her, and back toward an obscured Troy pinned to the driver's seat.
Tracy watches the "documentaries" on the camcorder. However, the series takes place over a decade since the Zombie Apocalypse occurred. Batteries, like gasoline, do not last indefinitely.
Car batteries go bad when a car just sits unused for months. At this point in the series, it is well over 10 years into the Zombie Apocalypse. Yet, early in the episode, a car is easily hot wired and the car starts.