All criticism of Tedder stems from his dislike of Montgomery. It had a long history. Tedder's personal assistant, who maintained his diary, was Wing Commander Leslie Scarman - later Lord Scarman, Law Lord and distinguished judge. Carlo D'Este interviewed Lord Scarman in 1980-81. His assessment of Tedder, in Decision in Normandy is based on those interviews:

Sir Arthur Tedder was no friend of Montgomery. The two men had once been close during the Alam Haifa and Alamein battles in 1942, when the RAF had provided impressive support for the Eighth Army. At the conclusion of Alamein, Tedder had written to Montgomery offering the full support of the air force in the pursuit of Rommel, which he urged to be undertaken at full speed. Montgomery resented receiving advice from an airman about his tactics and from that time forth relations between them cooled perceptibly. In the period before D-Day, however, Montgomery and Tedder worked together in a spirit of cooperation and relative harmony, but after D-Day things soured badly between them, with Tedder becoming Montgomery's most vocal critic at SHAEF.

This is the background to Tedder's criticism of Montgomery's command, and at the failure of operation Goodwood at Caen. Max Hasting's in Overlord (page 238) says that "As a result of Goodwood, Montgomery's prestige within the Allied command suffered damage from which it never recovered. Eisenhower was disappointed and angered by the gulf between Second Army's promise and performance. ... Tedder's animosity was redoubled. He considered that the air forces had been the victim of a deliberate deception by Montgomery, who had exaggerated his expectations merely to ensure that he received the support of the strategic bombers".

Max Hasting's concludes (page 242) "Tedder's allegation that Second Army was not trying hard enough had some foundation. But it was much easier to take this sanguine view from the distance of SHAEF - or from the perspective of history - than for Montgomery and his commanders in Normandy, who had to watch their precious army take persistent punishment. Tedder's attitude proved his claim to be an outstanding Alliance commander, with a truly Anglo-American perspective, but it showed little sympathy for valid but more parochial sensitivities".

Supporters of Montgomery will always view Tedder in a poor light. But to jump from this to calling him 'a reptile' is entirely unjustified. We should reserve such extreme terms for characters like Himmler or Göbbels, not for honourable and distinguished commanders.