Yes if I'd have found Willow and the phone, especially if I owned the caravan park nearby, I would have taken them with me so that they're safe and reunited with owner asap. It's a funny one though because finding both together would have probably set off alarm bells and I think I'd have called the police in that situation. Even if I was in a rush to an appointment. I'd never leave an abandoned dog alone for someone less loving to find them
ALSO, wouldn't Willow have had a phone number tag on her collar or if not harness? It's the law. So then why call the school.