In fact, ABB moved a substantial chunk of the plan's assets into the Fidelity funds when those funds were so new that it had to change its investment policy statement specifically to do so.

Another fault the court found with ABB: Fidelity specifically offered it a better deal to move those plan assets from Wellington to Fidelity, which constituted a conflict of interest for ABB.

The district court's decision found that ABB did breach its fiduciary duty by its actions, although since the plaintiffs failed to satisfy pretty narrow and stringent requirements for demonstrating financial damages incurred as a result of that breach that the court declined to award monetary damages.

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But ABB still erred, and Witz said it wouldn't have done so had it followed "past case law, as well as Department of Labor publications including the most recently issued Field Assistance Bulletin 2015-02," and held to six precepts.

Lest other fiduciaries end up following in ABB's errant footsteps, here are those six precepts.

1. Engage in an objective, thorough and analytical search.

ABB, according to the court, had "inconsistent explanations for removing the Wellington Fund and mapping its assets to Fidelity Freedom Funds."

That's hardly the sign of an objective, thorough and analytical search, which should have been able to inundate questioners with reams of data about why the Fidelity move might have been the right one for plan participants.

2. Avoid self-dealing, conflicts of interest, or other improper influence.

The district court's decision indicated that ABB failed to do this, particularly since the court found ABB was motivated to boost revenue sharing with Fidelity, which would result in higher profits and thus lower costs to ABB.

Another conflict resulted from the fact that, although ABB was paying lower fees, the plan participants whose money was mapped into the Freedom Funds were paying substantially higher administrative fees than they had with the Vanguard fund.

3. Consider the risk associated with the investment versus alternatives.

The Wellington Fund had a 70-year track record and an annual performance that beat Morningstar's benchmark by 4 percent at the time it was removed in favor of the Fidelity funds—which were far newer and thus had less of a track record by which to judge either performance or risk.

And despite recommending removal of the Wellington Fund for "deteriorating performance," the head of ABB's Pension and Thrift Management Group never provided any data to the investment committee to back up that description—not that the committee ever asked for such data.

4. Consider ALL costs in relationship to services provided.

The Wellington Fund's costs were lower than Fidelity's Freedom Funds because the Fidelity funds engaged in revenue sharing with Fidelity Trust.

Moving from Wellington to Fidelity lowered ABB's costs for nonplan-related services, thanks to the revenue sharing, but it substantially increased the costs to plan participants. For the Management Group, that was not sufficient cause to reject the mapping.

5. Ensure the investment is diversified to minimize the risk of large losses.

Diversification was not a consideration either in the choosing of the Fidelity Freedom Funds over the Vanguard Wellington Fund or in eliminating the Vanguard fund from the plan. In fact, the court described the Management Group's research of the investments as "superficial and cursory."

6. Consult with experts when that expertise is lacking.

Far from consulting with experts, ABB's investment committee did not even, according to the court's findings, consult with the Management Group—which was the only group looking for potential replacements for the Wellington Fund.

In addition, despite being advised by an independent human resources consultant that its plans looked as if they were overpaying for recordkeeping services and subsidizing corporate services that Fidelity was providing to ABB, neither the Management Group nor the investment committee ever bothered to calculate just how much Fidelity Trust's recordkeeping fees amounted to.