Buchanan said he made a mistake in reducing his contact with the team, giving them and assistant coach Jamie Siddons more responsibility.
"I'd lost touch with the players," Buchanan told the Kolkata-based Telegraphnewspaper when asked to spell out the reasons for the world champions' 2-1 defeat against their arch-rivals.
"It happened because Id pushed myself into a different role, which was to give the players responsibility for their game.
"Also, giving the assistant coach (Jamie Siddons) more responsibility. In doing so, Id removed myself from contact with the players.
"I learnt I had to re-establish relationships. That I had to change my role a bit.
"I finished the Ashes physically and emotionally drained. Looking back, I ought not to have retreated into myself the way I did.
"Yet, I cant be certain that the result would have been different had I myself acted differently."
Buchanan, whose contract was extended till 2007 by Cricket Australia despite the Ashes embarrassment, said the defeat may be a blessing in disguise for the team.
"We went to England with a lot of expectations and, quite simply, didnt meet the expectations," he was quoted as saying.
"We didnt win, but it was a tight series. The result, though, came as a golden opportunity. It has made me, the players, the support staff and Cricket Australia look at where we are and where we desire to be.
"It also made us look at England, made us look at other countries.
"We came up against an England team which was very well prepared. We should have looked at the little things which happen in and around our team. Perhaps, the team disciplines also ought to have been looked at."
Asked if he had been out-thought by his English counterpart Duncan Fletcher, Buchanan said: "Not out-thought, but outplayed."
"We understood what we had to do, but didnt put that into practice. England were well-tuned and delivered better than us.
"I accept England forced us to play catch-up-cricket. The good thing is that we fought back in every game, but that wasnt good enough."
Buchanan said the ability of English bowlers to swing both the new and old balls told on the Australian batsmen.
"The England bowlers swung the ball, old and new, and at good pace," he said. "You dont come across very many bowlers who do that in todays cricket. Outside England, I cant think of anybody other than (Sri Lanka's) Chaminda Vaas."
Australia bounced back from the Ashes loss to sweep the Super Series against the world teams this month, winning the one-dayers 3-0 and the six-day Test match by 210 runs inside four days.