As far as the cat failures go, it's possible they're related to Honda recalling a bunch of Civic Hybrids saying they were programmed to run too lean. Perhaps the fleet examples were running WAY lean and burned up the cats as a result?

Anyway, the only way to make best use of the figures for comparitive purposes would be to see the results of their non-hybrids and see how they were doing before. If they previously had a fleet of 10 Sentras and Corollas that all got 18-22mpg, then we'd know their style of driving is not well suited to getting high figures, but still that the switch to hybrids saves quite a lot of gas.