He took lighthearted jabs about which team he might play for next - the NSW Origin team, the Waratahs even the Western Sydney Wanderers - in his stride.
Hayne wasn't fazed when asked why he wanted to represent a country other than Australia - where he was born and raised and spent his entire life before moving to America last year. "Because they (Australia) didn't ask me," he said.
And he was happy to take questions about his playing ability. "I have confidence in myself," he said. "I know how to run, I know how to pass, I go all right."
Poor old Ryan was a different story.
As an experienced Sevens coach - he guided England from 2007 to 2013 before taking the reins at Fiji - Ryan has had plenty of practice dealing with the press.
He played ball when asked why his world-beating team wanted to include a player like Hayne, "if you are good, you want to get better", and continued to insist the Australian was far from being guaranteed a spot.
But facing up to a media scrum filled with London-based television journalists who - because they're required to cover all matter of world events - understandably wouldn't know a hooker from a winger, was a bit too much.
When one of the reporters dared to ask Ryan what his name was, his blood started boiling. When he felt they were rude to a security guard, that was it.
The Australian's European correspondent Jacquelin Magnay said Ryan was "feeling the pressure" and "stormed off".
"Ryan was initially upset because a TV reporter asked him his name, and then he claimed the media was rude to an over-officious security official demanding television cameras move a foot further back onto the pavement," Magnay wrote.
It wasn't all bad news for Ryan on Tuesday as World Rugby announced Hayne was eligible to play for his team at the Olympics and as early as the world series event in London this weekend.
Hayne, who played eight times with one start for the 49ers as a rookie last year, announced on Sunday he was quitting the NFL.
The 28-year-old former rugby league star said he was joining Fiji in the hope of making its squad for the Rio de Janeiro Games. Hayne qualifies for Fiji through his Fijian father, and has played international rugby league for the Pacific nation.
But questions were raised over his eligibility because he has not recently been part of a registered drug-testing program. A former head of the Australian Sports Anti-Doping Agency, Richard Ings, expressed doubts on Monday that Hayne would be able to make an immediate transition to rugby because the NFL was not compliant with World Anti-Doping Agency testing requirements. Ings said World Rugby required a player to be in a registered drug-testing pool for six months before becoming eligible to play in its sanctioned tournaments.
"If Jarryd Hayne had been playing in a WADA-compliant sport, he would have grounds to reduce the six months," Ings said. "But NFL is PED (performance-enhancing drugs) badlands. No chance."
Ings said rugby's six-month return to competition rule "is standard across most sports for athletes returning to international competition. And necessary." "The rule equally applies to reinstatement or to new players. Sensibly it must, or any NFL player could bulk up and play."
But in a statement on Monday, World Rugby said the six-months rule does not apply to a player "if they are being selected for international competition for the first time." "This position is entirely consistent with World Rugby's approach to other crossover athletes, including other ex-NFL athletes coming into rugby."
Fiji leads the world series, and will likely go to Rio as the gold medal favourite.
Ryan hailed Hayne's decision to switch codes but said he received no guarantees of selection.
"I have no promises he is going to make the 12, but we will see how he goes," Ryan said.
"He will then come into the Fijian camp for the Olympic period. It is a huge challenge for Jarryd but if he gets into the squad it is only going to be on form, because he is a blinding rugby player."
- With AP
