This was a standard technical phone screen, but its execution could have been better in a few ways:

• The interviewer had an accent, which on its own would have been fine. However, he was using speakerphone in a conference room, making it difficult to hear him. Anyone who has conducted several phone interviews knows what I'm talking about: there's a reverberation effect that significantly blurs the audio.
• The interviewer posed a question that was fairly visual, involving tasks on a map (think a cartographic map of land and sea, not a computer science map). This format does not lend itself well to conveying ideas over the phone. The question would have been more suitable for an in-person interview with a whiteboard, allowing for pointing and drawing.

A graph algorithm problem that can be solved with BFS/DFS.