Recently, it seems that the specification of Google Spreadsheet was updated. Before this, when a cell has only one hyperlink. In this case, the hyperlink was given to a cell using =HYPERLINK("http://www.google.com/", "Google")
as following figure.
But by the recent update, a cell got to be able to have multiple hyperlinks as following figure. In this case, the hyperlinks are set by the RichTextValue object.