One of Cellucci’s sharpest critics on this issue, State Treasurer Shannon O’Brien, concedes that the report doesn’t “outline [Cellucci’s] direct knowledge.” O’Brien will say only that the “very troubling” allegations represent “a violation of public trust.” The inspector general delivered his report to O’Brien because she — as the state’s highest financial official — had the obligation to sign off on state bond offerings for the Big Dig, something she refused to do while the phony numbers were being used.

In fact, O’Brien is the one who forced out news of the last $1.4 billion overrun in the first place. O’Brien says that she’d heard rumors of massive cost overruns from her own sources. She investigated the rumors and refused to sign off on a $496 million bond in February until she received firm numbers. This raises the question of whether Cellucci had this same information. The IG’s report suggests that he did, but it’s not a subject Cellucci has said much about.

WITH CELLUCCI’S nomination on the fast track, and some wiggle room left in Cerasoli’s report, does the governor get to ride off into the Canadian sunset? Well, yes and no. Mineta can still uncover something damaging in his probe. The transportation secretary’s inquiry, however, seems somewhat pro forma: Mineta, a California Democrat who accepted a job in the Bush administration, seems unlikely to burn up his political capital with the new president by going after Cellucci. Of course, there’s still the outstanding SEC inquiry. The SEC is one of the least political of the federal law-enforcement divisions — it’s less political than, say, the attorney general’s office, and it can levy civil punishments without the AG’s approval. Federal securities rules make it “unlawful for any person ... to make any untrue statement of a material fact or to omit ... a material fact ... in connection with the purchase or sale of any security.” A strict reading of this statute suggests that the governor could face liability if the SEC pursues Cerasoli’s allegations. Sources familiar with the investigation, however, say that several issues make such a pursuit unlikely. In the first place, the SEC would have to prove that bond-holders actually suffered as a result of the misrepresentation — and the state’s bond rating did not change. Second, the government is more likely to go after somebody lower down on the food chain than Cellucci, such as former Big Dig chief James Kerasiotes. In legal terms, it looks as if Cellucci walks.

A wild-card factor remains: if the SEC does come down hard on Kerasiotes, can it get him to roll on the governor? If Kerasiotes does a 180 and blames Cellucci for everything, the governor — or the ambassador — could be vulnerable. Kerasiotes, through spokesman George Regan, declined to comment for this story.

As for Cellucci, he doesn’t seem to be taking the report seriously. He told the Boston Herald that it was nothing more than a bit of “retaliation” by the inspector general: in January, Cellucci tried to cut off funding of the IG’s office. (Fran Brown, the first assistant inspector general, notes that the IG’s investigation began a year ago — long before Cellucci’s move.) In subsequent days, Cellucci’s aides have kept up the flippant rhetoric. “It’s like a bad term paper,” says spokesman John Birtwell. “[Cerasoli has] gathered little odds and ends and tried to paste them into a report to try in one last effort to make up for 10 years of inaction.”

Regarding the specific allegations about Cellucci’s knowledge of the cost overruns in 1999, Birtwell maintains that the governor told Wall Street exactly what he knew at the time: that while the costs could rise, the state’s analysis suggested that they probably would not. Under this defense, Cellucci’s partisans insist that what the inspector general considers hard figures were really just estimates. (Of course, as the report notes, the unpublicized overrun estimate made in 1994 brought the project total to $14 billion, a “figure uncannily close to the current $14.1 billion estimate.”) Cellucci’s defenders also point out that Cellucci’s leadership of the Big Dig Oversight Task Force involved coordinating environmental matters more than issues of cost.

But there’s still the matter of the mysterious timetable. Of this, Birtwell says only that “it’s a strange document.” Even after he was pressed for clarification, it wasn’t clear whether he was referring to the entire IG report, the specific document in question, or both.

Gregory W. Sullivan, the inspector general’s first assistant for financial investigations, finds all the governor’s explanations hard to believe. “Has it really come down to this?” asks Sullivan. “Governor Cellucci is accusing Governor Weld and many of his advisers of hiding the Big Dig overrun from him. It strains credulity.”

LAST MAY, Boston magazine profiled Weld. In his law office high above Manhattan’s Rockefeller Center, the former Massachusetts governor reminisced with political correspondent Rory O’Connor about his old days in the Commonwealth. In an offhand way, Big Red all but admitted that both he and Cellucci knew long ago about the cost overruns: “When Cellucci and I were out on the hustings in central and western Massachusetts, we didn’t want to tell the town fathers and mothers that we were going to take all their statewide road and bridge money and use it to pay for the Central Artery Project.” Soon, Cellucci will be in Ottawa doing Bush’s bidding. Perhaps he’ll also sip wine and laugh about the suckers back in Massachusetts. But Cellucci should be looking over his shoulder, and maybe Weld should too. We haven’t heard the last of this.

Seth Gitell can be reached at sgitell[a]phx.com.