It is no surprise that sensitive information flows between the points where Airbus and Boeing intersect with their interconnected web of suppliers, investors and customers. This is a game normally reserved for insiders, but occasionally a whisper spills out and becomes news. Either manufacturer may blush in embarrassment for a moment, but the industry moves on.
But the Airbus report, "787 Lessons Learnt", is altogether different. The document is a spectacular glimpse into the practices and methods of a corporate intelligence unit, revealing lessons to the general public far beyond the trials of the 787's troublesome development. It hints at how the game is played - at least by Airbus.
Despite damaging assertions about the 787, Boeing is clearly the winner in this round. By reading it, Boeing is afforded the rare privilege of learning exactly what its rival thinks it knows about the example of the 787. Perhaps more important, Boeing is allowed to see what Airbus doesn't know about the 787. In Seattle, any gaps in Airbus's knowledge could be even more instructive.
The document appears to betray some Airbus sources and methods, which at least raises questions about the airframer's code of ethics for intelligence gathering.
No-one begrudges Airbus's right to collect information about its competitor. But it does not explain how it obtained a series of internal Boeing charts marked "proprietary" - an omission that could haunt it in the US Air Force tanker competition.
Boeing, too, can learn lessons from Airbus intelligence.