JONNY Bairstow's behaviour in a Perth bar has left coach Trevor Bayliss struggling to contain his exasperation at the "dumb decisions" England players continue to make.

England's ten-wicket defeat in the first Test in Brisbane was completed on the fifth morning but the post-match media briefings were dominated by Bairstow's apparently playful 'headbutt' on Australia opener Cameron Bancroft on the opening night of the tour in Western Australia.

Bayliss agrees with the Yorkshire wicketkeeper-batsman in saying the matter has been "blown completely out of proportion", while Bancroft also bears no grudges but conceded it was a "weird" way to greet someone.

Bayliss began the Ashes trip by insisting he would still treat his players like adults in the wake of all-rounder Ben Stokes' arrest on suspicion of causing actual bodily harm in a late-night fracas in Bristol over the summer, an incident which has made the Durham man unavailable for the tour.

Asked now if he thought Stokes' experiences might have prompted the players to be more careful, the Australian said: "That was what I thought after Bristol as well. They'd be extra dumb and stupid if it didn't.

"That's the disappointing thing – we make dumb decisions. If you put yourself in that situation, you are fair game."

Bayliss believes nonetheless, like Bairstow, that the latest incident is being given more attention than it deserves.

He said: "I think there was some contact but obviously not a headbutt. There's a big difference. It's blown out of proportion but it gives the opposition ammunition to put pressure on as well.

"That night there was no curfew and there was absolutely no malice in it. But we can't put ourselves in these situations, however small they are."

Joe Root's team will be collectively reminded of their responsibilities by England and Wales Cricket Board director Andrew Strauss, while Bayliss has hinted that players may yet be advised not to drink on nights out.

"Most people like going out at night for a couple of quiet drinks but you've got to be careful you don't do anything stupid," he said. "If that means not having anything to drink, then so be it."

The matter came to light only when Australia were picked up on the Brisbane stump mic reminding Bairstow of his behaviour.

The York-raised player issued a statement about the incident, in which he said: "We were just in the bar, having a good laugh and a good evening out. It was very enjoyable.

"Cameron and I enjoyed the evening and continued to do so. There was no intent, nor malice, about anything during the evening.

"As you could see, out there (on the pitch), there is no animosity between myself, Cameron or any of the other Australian players.

"I hope we can now swipe this underneath the table, continue what is going to be a fantastic and exciting series – and we move on from there."

Yet Australia captain Steve Smith believes there have already been repercussions on the pitch, claiming it helped Australia dismiss Bairstow in England's second innings.

"I think it was basically about trying to get Jonny off his game and I think it worked, with the way he got out," he said.

"He got caught at third-man, playing a pretty ordinary stroke. We were just trying to get in his head and it happened to work."

Bancroft said of the incident: "He connected with my head. With a force that would make me think: 'Wow, that's a bit weird'. And that was it."