1. Such a style of recalling a past event is not unique to Deuteronomy. The Gospel of Matthew, e.g., shifts from its infancy narrative to the account of John the Baptist's ministry with the introductory "Now in those days" (3:1), which gives the impression that what follows—i.e., the ministry of John—occurred during the time of the preceding infant days of Jesus when, in fact, it did not.
2. Thus, J. A. Thompson, 85; P. D. Miller, Jr., 27ff.; C. Wright, 24ff; W. Brueggemann, 28, and J. G. McConville, 64ff. See also, e.g., the otherwise excellent exposition in Ajith Fernando, Deuteronomy: Loving Obedience to a Loving God (Preaching the Word; Wheaton, Ill.: Crossway, 2012), 45-62.