I've been involved in at least two accidents that were out of my control, one involving a car, and it was obvious in both cases that going slower saved my ass. I can see that below a certain speed you get more wobbly, but she seems to have been going in excess of 30 mph, at which point your own reaction time becomes the biggest issue.
I'm sorry, but no. Going over 30 mph does not make this her fault. And becoming "wobbly" at slower speeds is not the reason riding faster is preferable and safer on these stretches. It is because the biggest risk is the car closest to you, i.e. traveling in the same direction as you. The faster you are going, the smaller the delta in speeds, the less likely you are to be hit, and the less likely you are to die from the impact when you are hit. Driving at lower speeds because you are worried about the cars in the oncoming lane puts you at greater risk to the greater threat. And 30mph is not fast enough to negate your ability to react -- unless of course the situation does that for you in its entirety.
I'm not going to say definitively whose "fault" it was, but the car behind you is not the biggest risk. The biggest risks are almost always in front of you-- cars pulling out of intersections, opening doors, and cars making sudden right-hand turns into your lane without seeing you. This has been my experience and the statistics bear this out (http://bicyclesafe.com/).
If you're going to get hit from behind, it's probably because you swerved or a driver (going much faster than you) didn't see you and extra speed is not going to save you. Surviving the initial hit because you were riding fast doesn't mean much when your body slams into a guardrail or some other stationary object at 45 miles per hour.
I don't deny the risks you list, particularly when it comes to urban riding -- but on this particular stretch of road it is most certainly the cars behind you that pose the greatest risk. The cars at intersections are obviously a large risk as well, but it's offset by the fact you can see them, and thus react.
Makes sense, I missed the part where you'd specified that one stretch of road.
But still, although you can see cars at intersections, whether you see them in time to react is the important question and speed is a critical factor there.
