Aw that's such a good news story! Dogs can be so amazing. I had a crazy collie once who used to find her way home to me by visiting every house shed been to with me until she found me. Sometimes over a range of 50 km, like when I told her to stay outside the library at uni and she thought I'd left and took three days to get home when I thought I'd lost her.
Yay for people who look out for animals.