When they came up out of the water, the Spirit of the Lord snatched Philip away. The eunuch never saw him again but went on his way rejoicing. 40 Meanwhile, Philip found himself farther north at the town of Azotus. He preached the Good News there and in every town along the way until he came to Caesarea. Acts 8: 39-40

Philip’s sudden departure meant that the Ethiopian was unable to thank or reward Philip for his help. Instead of being focused in Christ as “he went on his way rejoicing”, which is much more important than Philip’s mode of travel.