Phil Andrews, Doug Duncan and Isiah Leggett have so far answered roughly nine hours of questions from moderators and audience members during campaign forums in the 2014 Democratic primary for Montgomery County executive.

But Sunday night’s joint appearance proved that moderation in all things is not necessarily a virtue. Allowed to question one another before an audience of Democratic activists, they produced some of the county political season’s most robust and revealing exchanges. Moderator Charles Duffy, host of “Political Pulse” on Montgomery Municipal Cable, wisely set them loose.

Former county executive Duncan reprised his query on the long-delayed Silver Spring Transit Center, but he got an unfamiliar answer.

“When’s it going to open? What’s it going to cost? What’s the detailed plan to fix it? And is it going to be safe?” Duncan asked.

“Maybe Mr. Duncan can ask Foulger-Pratt when they might be able to finish it up,” said County Council member Andrews, to scattered hoots and applause. It was a reference to the project’s heavily criticized general contractor, who was a private-sector consulting client of Duncan’s several years ago (on matters unrelated to the transit center).

County Executive Leggett, also responding to Duncan, insisted that the questions have been asked and answered. He said the county is planning to turn the facility over to Metro in the summer for an early autumn opening. But it won’t be up and running until it is safe, he said, and taxpayers will not be on the hook for additional expense because of poor work by contractors.

“I just want you to remember those answers,” Duncan said, “for when we find out what the real fix is going to be.”

Duncan decried what he called a “secret committee” overseeing the project, a reference to a working group of industry experts, headed by former Lockheed Martin chair and chief executive Norman Augustine. Leggett assembled the group without public announcement late last year to review repair plans.

“Hopefully, we will get that report soon,” Duncan said. “I’ve asked him [Leggett] to make it public.”

“I think you have a problem with hearing here,” said Leggett. “All this talk about some secret commission? What are you talking about? We haven’t engaged in some conspiracy here.”

Duncan: “The lack of execution by the executive when they signed the construction contract in 2008 has been horrible. Lack of oversight by the County Council has been pathetic. They’ve not done what their duty is.”

“Will you make public the Augustine committee’s report?” Duncan asked.

“I don’t know of any report,” Leggett said.

In fact, Augustine said last week that he hopes to submit the panel’s report to Leggett sometime in the next couple of weeks. (Leggett backtracked after the debate, saying he wasn’t sure if it was going to be a formal report, but that “what we get will be made public.”)

Leggett also stumbled in describing the work that remained on the transit center. Because of cold winter temperatures, he said, “we’ve waited until we can add the last aspect,” referring to the new layer of latex-modified concrete that workers will put down to address serious cracking in the concrete.

Leggett failed to say that Montgomery and Metro still haven’t decided what to do about interior beams and girders that the county’s engineering consultant, KCE, recommends be reinforced against torsion, or the twisting forces to be generated by hundreds of buses traveling the center’s roadways every day. Augustine’s report is expected to address the issue.

Andrews said that both Duncan and Leggett have tried and failed to execute the project. It languished on Duncan’s watch, delayed by disputes over design and changes in scope. Leggett’s troubles came after ground was finally broken in 2008. The KCE report cited faulty design by Parsons Brinckerhoff and poor performance by Foulger-Pratt. Both firms dispute the findings.

For his question, Leggett confronted Duncan with Washington Post stories from 2004 and 2005 reporting that during his third term as county executive Duncan had dipped into cash reserves to spend more than $43 million for cost overruns on a series of construction projects, including Strathmore Hall.

Leggett’s decision to invoke Strathmore undercut statements he made last month in a forum at Leisure World, where he effectively defended Duncan by explaining that added expenditures are sometimes unfairly depicted as overruns. Such figures, he said, are often based on early, partial estimates of the true cost, which often isn’t known until a project is well into the design phase.

Drawing from the earlier Post articles, Leggett said Duncan had earned “a C rating from Syracuse University.” This was a reference to a 2003 study by Governing Magazine and Syracuse’s Maxwell School of Public Affairs that gave the county a “C” grade for capital management on Duncan’s watch. Leggett did not note that the same survey awarded a B for Duncan’s financial management.

“I really don’t care what Syracuse University said in 2004. This is 2014,” said Duncan, who on Sunday released booklet of policy proposals he called “Leadership in Action.”

Leggett again raised his assertion that Duncan had left the county broke at the end of his three terms in 2006, brandishing an Excel spreadsheet that he said his campaign would circulate.

“That’s the record,” Leggett said. “We’re not talking about games and wish lists” and what he described as“smoke and dagger” on Duncan’s part.

Records show that in the fiscal year ending June 30, 2006 — Duncan’s last full fiscal year in office — there was $107.8 million in the county’s rainy day fund, also called the Revenue Stabilization Fund. The general fund had an unexpended balance of $244.8 million for a total of $350 million. Leggett drew $44.8 million from it in 2010 to help make ends meet during the Great Recession, records show.

Andrews, who has made fiscal restraint his cornerstone message, asked Leggett what he was thinking in 2009 when he made a deal to contribute $7 million to county employee pension funds based on raises they never received. Andrews ultimately led a move that outlawed “phantom” payments.

Leggett explained that it was an attempt to compensate for the unions’ agreement to relinquish a portion of negotiated raises to cut costs during the recession.

“We were trying to provide some level of relief over a long period of time to employees,” Leggett said of the pension boost. He said was also trying to keep the county out of binding arbitration, to which unions are entitled by law in labor disputes. The county usually loses in those proceedings.

Andrews suggested Leggett was using binding arbitration as “an excuse.”

Earlier, in the moderated portion of the debate, Andrews said that he was better positioned to negotiate with unions because he took no campaign contributions from organized labor. Leggett accused him of naivete about the arbitration rules.

“So the idea that you’re going to get tough, that you’re going to negotiate with someone and get the results that you describe is not reality...Because your positions are so extreme as it relates to labor.”