Jonny Bairstow 'headbutt' something he does with his rugby mates, says Andrew Strauss
England's Jonny Bairstow "bumped heads" with Australia's Cameron Bancroft in a bar because it is "something he does with his rugby mates", according to director of cricket Andrew Strauss.
The squad are effectively grounded after the incident in Perth in October - and Strauss said they are not "using their intelligence in the right way".
Ben Stokes was arrested on suspicion of actual bodily harm in September.
"Quite frankly, we need to sharpen up our act," Strauss told BBC Sport.
All-rounder Stokes, 26, is not part of England's Ashes tour as he awaits the result of a police investigation.
After England's 10-wicket defeat by Australia in the first Test on Monday, Bairstow said the incident with Bancroft - which took place on the first night of the tour - was "blown out of all proportion".
Bancroft, 25, laughed off the incident, while he and Bairstow said there was "no malice" intended.
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Why would Bairstow 'bump heads' with someone?
Strauss said he had "no idea" why Bairstow, 28, would make such a gesture.
"It's something he does with his rugby mates," said former England captain Strauss.
"It was a jest, a joke. It's just a little bump of heads. It's not a headbutt. I don't think it's been reported accurately.
"When people mention a headbutt, there's a connotation around aggression, malicious behaviour, intent to hurt. It was anything but this.
"He was completely baffled, surprised and shocked that this was a massive issue."
Strauss said Bairstow, who made nine and 42 at the Gabba, was "embarrassed and shocked".
"He's pretty contrite right now. He understands that it wasn't the most sensible thing for him to," Strauss said.
"As we've seen from the way Cameron Bancroft has reacted, there was no offence taken.
"It's a minor issue but it highlights the fact that minor issues can become major issues."
The Stokes incident took place outside a Bristol nightclub, while the Bairstow episode took place in a bar in Perth as Bancroft and his Western Australia team-mates celebrated victory over Tasmania in the Sheffield Shield, Australia's domestic competition.
Strauss denied that there is a drinking culture within the England team, but said players must be "smarter" with the situations they place themselves in.
"What might have been acceptable in the old days is no longer acceptable," he said.
"They are adults - intelligent adults - and sometimes they are not using that intelligence in the right way.
"The last thing any of us want is to be in the news for the wrong reasons and I will be reminding the players of their obligations."
'These guys are not thugs'
Michael Vaughan, an Ashes-winning captain like Strauss, said the public perception of the England team has been damaged.
"They train as hard as any other England team I've seen," Vaughan told BBC Radio 5 live. "They are professional at the right times.
"What surprised me is that, after what happened with Stokes, they arrived in Australia and were allowed to go straight out to a bar."
Strauss said: "These guys are not thugs. These are good, honest, hard-working cricketers who sacrifice a lot to play for England.
"The perception of the players and the reality of who I know them to be is different at the moment.
"Their job now is to ensure that people look at them for what they really are rather than what they are perceived to be."
The second Test of the five-match series - a day-night encounter at the Adelaide Oval - starts on Saturday at 04:00 GMT.
- Listen to the Tuffers & Vaughan Cricket Show on 5 live - 21:30 GMT, 27 November
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How the Bairstow incident unfolded
28 Oct - Joe Root tells a pre-Ashes news conference that England do not have a drinking culture.
29 Oct - England land in Perth, Australia. Players go to a local pub in the evening.
29 Oct - Bancroft and team-mates celebrate a win for Western Australia against Tasmania in a domestic game, and end up in the same pub as England players. Bairstow greets Bancroft with a 'headbutt'.
1 Nov - Bayliss (unaware of the incident) tells BBC's Test Match Special that England players have come up with their own "sensible" rules around drinking, but there will not be a curfew in place on tour.
21 Nov - Australia spinner Nathan Lyon says his side will "headbutt the line, but we won't go over it" when asked about sledging on the eve of the first Test.
26 Nov - Bairstow is sledged during the fourth day of the first Test. ECB says it will investigate reports of a headbutt.
27 Nov - Bairstow, Bancroft and England coach Trevor Bayliss address the media, all playing down the incident.