I have had a similar experience.
A few months ago, waiting at the library to get my books checked out, I noticed a blind man who'se guide dog had turned the wrong way and was walking him away from the exit - a librarian showed him the right way.
When i came out about ten minutes later, he was standing on a traffic island, with his dog sitting by his side. I approached him, and he confessed that his dog seemed to be having on 'off' day, and had got him totally lost. I walked him to where he was going, but it did make me wonder how long he would have had to wait for someone else to come and offer assistance.
We really don't know how lucky we are.