Couple of points:

If the mention of him being helmetless is irrelevant (I'm assuming there's no MHL in effect - they never mention that) then isn't mentioning the fact that she was driving an SUV equally irrelevant?

She was charged with DUI after refusing a breathalyser. I doubt that would be sufficient reason alone to charge someone. There must have been other factors that led the officer to believe she was under the influence - or am I being hopelessly naive?

Riding at night without lights or reflectors is stupid and dangerous, but that doesn't necessarily mean he was invisible. Was there street lighting? What colour was his clothing? If the driver is found to have been DUI, then surely she should also be charged with involuntary manslaughter as well despite the cyclist's negligence. Call me idealistic, but I don't think anyone should get away with killing someone whilst driving drunk under any circumstances.