I actually read all the comments...unfortunately. It's easy to get sucked in.
According to a comment from someone who claims to have seen her ride off that night, she was wearing "light-colored clothing" and had a red bandanna attached to part of the bike. No mention of lights, which would possibly make this (legally) the cyclist's fault. According to the wording of the following quote, I believe a taillight is mandatory in Ohio.
"§ 4511.56. Bicycle signal devices.
(A) Every bicycle when in use at the times specified in section 4513.03 of the Revised Code, shall be equipped with the following:
(1) A lamp mounted on the front of either the bicycle or the operator that shall emit a white light visible from a distance of at least five hundred feet to the front and three hundred feet to the sides. A generator-powered lamp that emits light only when the bicycle is moving may be used to meet this requirement.
(2) A red reflector on the rear that shall be visible from all distances from one hundred feet to six hundred feet to the rear when directly in front of lawful lower beams of head lamps on a motor vehicle;
(3) A lamp emitting either flashing or steady red light visible from a distance of five hundred feet to the rear shall be used in addition to the red reflector. If the red lamp performs as a reflector in that it is visible as specified in division (A)(2) of this section, the red lamp may serve as the reflector and a separate reflector is not required."