Historians are gradually coming round to endorse David Irving's viewpoints.

[...] According to the published version of the OKW war diary, Hitler promptly discussed the overall situation with the general staffs of both army and air force, but, "as usual, again no bold decisions are taken. It is as though the Führer is no longer capable of doing so." (81) As David Irving points out, however, this frequently cited passage is a postwar interpolation designed to cast Hitler in a poor light. It does not appear in the original, unpublished manuscript by Helmuth Greiner, the OKW's diarist, and it is inconsistent with Hitler's recorded actions on the days both preceding and following 21 December [1942].(82) Rather than vacillating, the Führer stood firm, repudiating the "defeatist" views of his generals with typical dogmatism. He strongly disagreed with Manstein's and Zeitzler's assessments and rejected their suggestions. Still determined to hold Stalingrad, the only major prize of an extremely costly summer campaign, he insisted that Sixth Army might attempt to join up with Hoth's corps only if it continued holding its positions on the Volga.

[Endnotes:]

81. KTB OKW vol. 2, 1168 (21 December 1942).

82. Irving, Hitler's War, 453. Irving is correct. An examination of the original manuscript (David Irving, Microfilm DJ-91, part of the Irving microfilm series "Records and Documents Relating to the Third Reich" by Microform [Wakefield] Ltd.) reveals that the published version differs in many places from the original manuscript and that all changes cast Hitler in a negative light.

DAVID IRVING COMMENTS:

I was the first historian to draw attention, in my Introduction to Hitler's War, to the large number of faked or partially faked diaries in circulation, like those of General Gerhard Engel, Hitler's army adjutant, published by the Institut für Zeitgeschichte (who should have known better: I warned them).

Helmuth Greiner was a war diarist attached to the High Command (OKW). After the war he reconstructed his missing 1942-43 OKW War Diary from his pencilled draft, and it formed one of the lavishly bound five volume published set of Kriegstagebücher des OKW.  Because it was fashionably critical of Hitler's achievements, it provided a useful source for other historians -- until I came along and checked the published text against the wartime hand-written original, with the results that Joel Hayward, a young (Jewish) New Zealand historian confirms above.