World Cup bosses have already launched an investigation into the incident, which occurred late in the second half when England substitute Dan Luger came onto the field, while centre Mike Tindall was being treated for an injury.
As no England player left the pitch, that meant that for approximately 34 seconds, England had 16 players on the field.
This is a major embarrassment for a team famed for their scrupulous attention to detail and England supporters will be keeping their fingers crossed that the incident does not have a major impact on the Men in White's RWC campaign.
"It was an error, I can assure you," Woodward told zurichpremiership.com.
"Yes, there has been an investigation, I have only just found out about that and obviously we are co-operating fully with that investigation and that is all I can say.
"I would like to think that if any team made an error like this that there has got to be an inquiry and no more than that. And clearly we are going to fully comply with what the inquiry want to do and with the detail of what actually happened and that is all I can say at this stage.
"I don't know how serious this inquiry is going to be, I just know the facts from our side of things. And we are putting our report together it is as simple as that."
Meanwhile, ahead of their final pool match, against Uruguay in Brisbane, the England squad are continuing their training on the Gold Coast.
"There is a lot of conditioning work, but they will be doing no actual rugby work till Friday, when we will do two sessions in preparation for the Uruguay game. Train Friday morning and Saturday morning and the game on Sunday," said Woodward.
"This was all planned in, we were hoping that we would be in this situation when we had won our first three games and that we were going to stay up here to play Uruguay and hopefully stay up here to play the quarter-final in Brisbane."