He is saying the opposite. The downtown train arrives on the hour and the uptown train arrives at 5 minutes after the hour.

The description has it the other way.

"The solution is that, even though the trains arrive with the same frequency, the downtown train departs just a few minutes after the uptown train has departed. Because of this, there is only a narrow time window in which the man is able to get on the uptown train."

s/after/before/ to fix the explanation.

No, he does not say the opposite:

>even though the trains arrive with the same frequency, the downtown train departs just a few minutes after the uptown train has departed. Because of this, there is only a narrow time window in which the man is able to get on the uptown train.

He should say it like you suggested though.

You're right. I was looking at the diagram. Clearly the author accidentally swapped the two names in that sentence.

You are correct, he messed up telling the story.