Stuart Lancaster could not hide his frustration over England's lack of discipline in their 25-28 World Cup defeat to Wales.
The main bone of contention in Saturday's match at Twickenham came when England turned down the opportunity to take the three points after being awarded a penalty shortly after Wales had taken the lead.
Instead, they attempted to go for the try but were driven into touch from the lineout by ferocious Welsh defence, ruling out any hopes they had of snatching the game in the dying moments.
Lancaster, however, was more concerned with the errors they made throughout the 80 minutes.
"On the field, it's the players making the decisions and it was a big call to go for the corner," he said. "It's great if you score it, if you don't it's a big moment. Obviously, it was a huge moment in the game.
"I'm so frustrated to have allowed Wales back into the game in the way we did. We've talked a lot about discipline and breakdown penalties, and we gave some dumb ones away which kept them in the game.
"We were going well but ill-discipline from us and Dan Biggar's great goal-kicking kept them in the game, and from there, they got the try and suddenly (it was) 28-25."
Lancaster also defended his decision to make substitutions, rather than stick with the side that had put him ahead.
"We had a lot of injuries ourselves," he added. "Ben Youngs is an injury, Courtney Lawes is an injury, Tom Youngs had cramp so we accumulated the same sort of attrition during the game.
"A lot of the decisions I'm making are based on physios, Billy Vunipola is another injury. There's some battered and bruised bodies in there and that's ultimately what drives your decision-making."