When the wife kills the husband with the axe right after he shoots the goat, there is no visible blood on the axe after she pulls it from his face.
Ruiz aims a shotgun at a goat. Seen from behind the gunman, the goat's horns appear to be growing from the man's head. While it is a clever shot, from no other angle are the horns the correct shape for it to happen.
The background footage during driving scenes is obviously a low-resolution video.