(1) In sentencing a child for an offence, if the Children's Court imposes a less severe sentence than it would otherwise have imposed because of an undertaking given by the child to assist, after sentencing, law enforcement authorities in the investigation or prosecution of an offence, the Court must cause to be noted in the records of the Court—
(a) that it is doing so; and
(b) the fact that the undertaking was given and its details.
(2) Nothing in subsection (1) requires the Children's Court to state the sentence that it would have imposed but for the undertaking that was given.
(3) The failure of the Children's Court to comply with this section—
(a) does not invalidate any sentence imposed by it; and
(b) does not prevent a court on an appeal against sentence from reviewing a sentence imposed by the Children's Court in circumstances where there has been a failure to comply with this section.