Oh the tyre story/ car angle is interesting... maybe they were driving on the beach or somewhere you shouldn’t be driving and she was walking there and was hit? And the rough terrain snagged their car tyre and they’ve freaked out about what happened - they stopped to see if she was ok, she wasn’t... and one of them has tied up the dog then??? But that doesn’t account for the Police angle of ‘anyone with injuries’ line of questioning.