I'd argue innocence until I was blue in the face, literally in this case. It's the principle that matters.

This example isn't quite on the same level but the principle is the same. My mate is facing charges due to accidentaly knocking down a cyclist on the road that didn't have any lights on at night. It's obviously the cyclist's fault but because we're living in a compensation culture he's spun the story and my mate is coming off worse. If he simply pleads guilty he's going to get off better than if he pleads innocent due to lawyer costs. My area is financially quite poor and we simply can't afford to even challenge these decisions.