Coaches usually go out of their way to protect their team, specific players, and downplay any obvious weakness.
Here, in the aftermath of England's stunning second half capitulation against Scotland at Twickenham, Jones laid bare the demons forming his most pressing challenge after near embarrassment.
"It's like we have some hand grenades in the back of a jeep, and sometimes they go off when there's a lot of pressure," Jones said after England squandered a 31-0 first half lead and replacement first-five George Ford snatched a late, face-saving 38-all draw.
"We have a few of them, and we've got to get rid of them. It's the way you think under pressure. The team has probably had it since the 2015 World Cup, and we've been working on a process to fix it and we will get it right, but it takes time."
Time is running out.
World Cup-winning teams have influential, experienced, calm leaders at their core. Four years ago the All Blacks were led by Richie McCaw, Dan Carter, Ma'a Nonu, Conrad Smith, Kieran Read, Dane Coles and Ben Smith.
England's 2003 champions featured Lawrence Dallaglio, Martin Johnson, Jonny Wilkinson and Neil Back.
Do England now have comparable leaders? Their 27-year-old captain, Owen Farrell, looks more fallible than most at present. That also reflects those around him, and perhaps the inherent confidence and trust from top down when heat comes on.
With this gripping match locked 31-31, Jones hooked Farrell, his much-lauded playmaker, after he was upstaged by Scottish magician Finn Russell, and again showed his penchant for no-arms tackles.
Injecting Ford was bold and this time paid off, but it does not bode well for what is to come this year.
"He's a young captain and I think he's developing really nicely," Jones said. "I'm very pleased with him. Like any young captain it takes time. You don't put a C next to someone's name and they learn every lesson on how to manage a game."
After a Six Nations in which England finished second - to Warren Gatland's Welsh grand slam champions – due to their failings in the Cardiff cauldron and this final match, major questions linger about their temperament.
Do they have the stomach, the ice-vein composure for much more daunting challenges?
World Cups define pressure, after all.
England developed aspects of their game in this tournament – their breakdown work, set piece and attacking strikes were all impressive at times.
Jones also emphasised: "We are going to have the players for three months, which I've never had before."
All the physical prowess counts for little, though, without unwavering belief in the face of consuming tension.
Unless this vulnerability is swiftly healed, mental scars from the last World Cup, where England failed to escape their pool at home under Stuart Lancaster, may haunt them.
France and Argentina will be no easybeats in Japan. Make it through those, and the burden and knockout fear awaits. This is no place for the faint-hearted.
Jones referred back to his time in charge of the Wallabies (2001-05) to detail England's composure issues.
"We managed to win 45% of tests against the All Blacks and they were all in the final 20 minutes of the game, and you could get them if you put enough pressure on them.
"It took them eight years to learn how to get out of it. Now we don't have eight years, we've had four years and we're still learning now, and we've got to do it in half the time it took the All Blacks to learn it.
"So this is not a new problem that we've got, this is consistent in teams and it takes time to fix. You just don't go like that and fix it. Do you know how many World Cups it took the All Blacks to fix it? So get some perspective about what we're talking about here."
With four warm-up games before the World Cup, Jones now plans to hire more mental skills specialists to absolve England's greatest weakness.
England already have former St Helens rugby league forward Mark Edmondson working with them in this space so whether the latest addition to this turbulent management group can perform some form of psychological Houdini act, Jones sure hopes so.
"Well it's a combination of personnel, but I've got one person that's going to help us that's a bit of an expert.
"If we can get some consistency in the way that we think on the field and that toughness and discipline about doing the right thing, we've got a team capable of winning the World Cup."