Which text uses the word disinterested in its traditional sense?

 - As a teacher of American history, Mr. Ferguson tries to remain disinterested when discussing controversial issues, giving equal attention and consideration to each major viewpoint.
 - As an experienced teacher of American history, Mr. Ferguson believes that playing history-based trivia games will revive even the most disinterested of students.
The first text uses disinterested in its traditional sense: unbiased or impartial.
As a teacher of American history, Mr. Ferguson tries to remain disinterested when discussing controversial issues, giving equal attention and consideration to each major viewpoint.
The second text uses disinterested in its nontraditional sense: uninterested or indifferent.
As an experienced teacher of American history, Mr. Ferguson believes that playing history-based trivia games will revive even the most disinterested of students.
Most style guides recommend to use the traditional sense of the word disinterested because it is considered more standard.