Is Biblical Eisegesis Ever Permissable?

Apparently the Old Testament scholar Gerhard von Rad's reading of Deuteronomy bordered on eisegesis rather than sound exegesis:

In his hands, Deuteronomy became not a law book demanding obedience, but rather a collection of sermons pervaded with a spiritual, even a "'protestantische' Atmosph�re."4 Written laws became homiletic sermons meant to encourage and inspire. Israel's obligation under YHWH's covenant treaty for obedience to his statutes and ordinances became Israel's unconditional election to salvation. On that basis, any sections of Deuteronomy that seem to make salvation dependent on works, i.e., obedience to the law, were deftly and systematically explained away. Either their significance was deemphasized, or they were relegated to later exilic or post-exilic expansions of the text, like the blessings and the curses of Deut 28.5 The support for these claims is often absent, so that von Rad's analysis of Deuteronomy, particularly the legal corpus of Deut 12-26, comes closer to eisegesis than to exegesis.

To be fair von Rad was trying to buck up against the Nazi idealogy that was so prevalent in his day---in his reading of Deuteronomy, von Rad was trying to reclaim the Old Testament from Nazi corruption and return it to it's rightful Jewishness:

From 1933 until 1945, the Hebrew Bible and the connection between Christianity and Judaism came under attack in Nazi Germany. Gerhard von Rad defended the importance of the Old Testament in a courageous struggle that profoundly influenced his interpretation of the book of Deuteronomy.

Gerhard recognized the importance of his work for:

(he) kept returning to Deuteronomy throughout his career, beginning with his doctoral dissertation in 1929, Das Gottesvolk im Deuteronomium, and continuing through Das formgeschichtliche Problem des Hexateuchs (1938), Deuteronomium Studien (1947), and his commentary on Deuteronomy for the prestigious series Altes Testament Deutsch (1964).2 Perhaps more striking than his preoccupation with this pivotal text, however, is the way von Rad characterized its textual content, its priorities, and its theology. His rhetoric frequently took the form of a series of antithetical formulations: Deuteronomy is not X but is Y.3 At times it seemed that von Rad was concerned just as much to establish what Deuteronomy is not as to show what it is. As is well known, von Rad argued that Deuteronomy is not law but rather a series of sermons by traveling Levites preaching a renewed message of redemption. He maintained that Deuteronomy's law code is not a dead text but live instruction, not demands for obedience to incomprehensible requirements, but spiritual exhortations to remember God's grace.

So do you think what he did was right or not?