Halliday & Matthiessen (2014: 532):
The intonation pattern of free indirect speech is still further anomalous, since it follows that of quoting and not that of reporting: the projected clause takes the intonation that it would have had if quoted (that is, identical with its straight, unprojected form), and the projecting clause follows it as a ‘tail’. This is because the projected clause still has the status of an independent speech act.