With his captain Steve Smith sat beside him laughing, Bancroft recalled the meeting that prompted sensational reports in the Australian media on the eve of the home side's victory in the first Ashes test at the Gabba.
"I got into a very amicable conversation with Jonny, he just greeted me with a headbutt," Bancroft told a news conference.
"I was expecting a handshake. It wasn't the greeting I'd expected. We continued on having a very good conversation.
"At the time he said sorry. For me personally it was just really weird. It was so random and I didn't really expect it.
"A handshake or hug would have been something more I would have expected. I just took it as, 'he says hello to people very differently to others'."
Bairstow said the incident had been "blown completely out of proportion".
"We were just in the bar having a good laugh. Cameron and I enjoyed the evening and continued to do so. There was no intent or malice," the 28-year-old told reporters after England's 10-wicket defeat.
"Hopefully now we can sweep this under the table and continue what will be an exciting, fantastic series."
England coach Trevor Bayliss said the players had not been under curfew in Perth and Bairstow had not breached the code of conduct so would not be disciplined.
"As he said, there was absolutely no malice in it," Bayliss added.
"I think there was some contact but obviously not a headbutt. Yes, it is a distraction.
"That's the disappointing thing, that's what we've got to be better at. We can't put ourselves in these situations no matter how small."
England captain Joe Root agreed and said the Australian players had brought up the incident on the field during the test.
"It's obviously disappointing that we've given them a good opportunity to bring something up," Root said.
"We've got to be careful not to make a big deal for something that wasn't there. I think it was just a bit of joshing around, boyish behaviour."
Smith said he had tried to use the incident to unsettle Bairstow, who made 42 in his second innings before hitting the ball straight to Peter Handscomb.
"I was trying to get at Jonny ... He got out at third man, it was a pretty ordinary shot," Smith added.
"We were just trying to get into his head and I think it worked."
Root was keen to quash comparisons with an incident during the 2013 Ashes series in England when the Yorkshireman was punched in a bar by David Warner, resulting in the now Australian vice-captain being stood down for two tests.
"I could see why people would see that on the surface," he said.
"There's two very different incidences and we have got to be very careful that we don't fall into that trap ... They were very different."
First Published: November 27, 2017, 9:01 AM IST