Allenby said he was drugged, kidnapped, robbed and beaten following a night out in Honolulu in January, in a mysterious misadventure the 44-year-old says he doesn't remember.
There is still confusion over how the night unfolded after a number of witnesses gave conflicting accounts.
But Allenby's former caddie Mick Middlemo, with whom he fell out spectacularly following a verbal confrontation during the opening round of the Canadian Open, said he had protected the golfer and publicly supported his story about the incident because he was asked to.
"Do I think he got mugged and bashed and absolutely robbed? No I don't," Middlemo told News Corp Australia.
"That's the story I told because that's the story he told me to tell because I wasn't there.
"Do I think he just fell over and cracked his head? Honestly I do. I think he fell over and someone picked up his wallet and had a great time with his credit card."
Middlemo took a further swipe at Allenby, describing him as the golfing equivalent of controversial tennis star Bernard Tomic, saying he gives Australians a bad name.
"The way he talks to people on the golf course is mind-boggling. To marshals, volunteers," he said.
Middlemo's comments come only days after he was sacked by Allenby, when he left the golfer's bag to walk off following a blazing row at Glen Abbey in Ontario.
Allenby allegedly called his fellow Australian a "fat c***" and threatened to have him "banned for life" from the PGA Tour.
But Allenby said he sacked Middlemo after the caddie started behaving in a threatening manner and "just lost the plot".
