The fact that something is legal doesn’t necessarily make it a good idea.

The City Council argues it made a defensible decision in hiring a particular attorney — one who will defend the city against a lawsuit charging that its votes on the rail project are invalid.

But in this case, Council leaders should have stopped and considered the ethical cloud already hovering on the project from the taxpayers’ viewpoint. Ultimately it’s hard to imagine there wasn’t a better option here, another firm that could have been hired.

At issue is the decision to hire the firm Starn, O’Toole, Marcus & Fisher to counter the complaint filed by Abigail Kawananakoa. The Campbell Estate heiress has charged that several Council members violated the ethics code in accepting gifts from parties advocating for the project.

The problem: Ivan Lui-Kwan, a board member for the Honolulu Authority for Rapid Transportation and its former chairman, is a partner in the same firm as the attorney being hired, Mark Bennett.

The law firm will be paid up to $100,000, under a resolution the Council approved last week. The measure establishes that Bennett and other partners will be paid $375-$500 an hour for the work, with lesser rates paid to associates and paralegals.

The firm must have realized how this looked, because its principals say it will set up a legal screen to block Lui-Kwan from having any involvement with the case. And Donna Leong, the city corporation counsel, said that there is no conflict of interest.

But the fact remains that the law firm of one of the project’s top authorities will benefit from the contract. And that outcome should have been avoided, especially considering the ethical track record here.

First, there’s Kawananakoa’s lawsuit itself. The Council is being accused of taking key votes on the rail project after having improperly accepted gifts from lobbyists and others who would benefit from those decisions. This potentially compromises the votes on numerous bills, with repercussions on its financing arrangements.

The cleanest solution would be simply to re-vote the measures, but the Council leadership seems unwilling to move quickly toward resolution. Leadership has even sought, unwisely, to divert some of the proposed tax-increase funds to non-rail city projects.

Further, Chuck Totto, the director of the city Ethics Commission, has raised his own concerns on the same issues, but the commission has dispensed with that objection without the transparency one expects of an ethics panel. It voted to dismiss those complaints against Council members after a closed-door hearing.

The attorney defending the three accused in the ethics case — Ann Kobayashi, Ikaika Anderson and and former Council member Donovan Dela Cruz — is Colleen Hanabusa, herself a member of the HART board.

At best, the taxpayers must wonder what’s going on. Outspoken critics of the project already have concluded that it means the fix is in.

The rail project is important to Honolulu’s development and transportation infrastructure. Given that, part of the city’s responsibility is to see that it’s carried out in a manner that engenders public trust.

This is not the way to restore that trust, which has been shaken as cost estimates rise and the process of decisionmaking and hiring seems all too slick. And this is a Council that maintains it wants more fiscal control of the rail project.

Before the Council takes any more votes of this sort, political insiders have to realize how inappropriate these decisions seem from the outside. Taxpayers deserve a process that’s beyond reproach — and the Council hasn’t delivered.