Yes, Meg Whitman's ad (above) attacking Jerry Brown for his very occasional use of a state plane is unfair. But the fact that the ad was made -- and might even be effective politically - is mostly Brown's fault.
At a time when California is facing big, systemic problems, Brown has made his campaign very small and very personal. This has been his way of protecting himself politically: avoid divisive questions about the state's broken budget system and instead talk about his colorful personal history as a tightwad governor.
So when Whitman dings him on these minor details (it was Brown who made a fetish of not using state planes), it's very hard for him to make the natural political pivot to say: She's lying and talking about minutiae while I'm talking about the big things we need to fix this state. Because he's not talking about those big things.
Brown's campaign is too small, too cheap, and ultimately too clever for its own good. In this way, it mirrors what was really problematic about his first governorship. Back then, in his determination to show himself as a differnet kind of Democrat who could win national office, he held the line on government spending to the point that infrastructure was underfunded and a giant surplus built up, fueling the tax revolt that produced Prop 13.
His own campaign, with all the delays and the refusal to put together a proper campaign infrastructure and above all the avoidance of big issues, raises fears not only about Brown as a candidate but also about whether a second Brown governorship would be too much like the first.