If I am the approaching vehicle and someone legally on the road ahead of me is travelling slower than me (bicycle or pedestrians included) and I run into or over the one in front of me it is almost assured that I am at fault. Bicyclists use this to their advantage all the time.
I have investigated many boating accidents and in every case the boat that was approaching from behind and collided with a watercraft going the same direction the overtaking boat operator was at fault.
I haven't read this whole discussion but I'm assuming the old woman didn't jump out in front of the bicycle when she turned to look. Sounds as if the bicycle was going to barely miss her at best if she hadn't turned to look.
I pulled the path up on Google street view. It's winding, narrow and tree lined. It also has stair access from the homes on the bluff above it. It's a horrible place to go fast on a bicycle.
The Louisiana maritime attorneys that I have discussed accidents with are quick to tell you that when the accidents get litigated, fault is almost always apportioned. The vessel being overtaken will always be the stand-on vessel, so that does put the brunt of the responsibility on the give-way/overtaking vessel. It does not however, absolve the stand-on vessel of attending her responsibilities as prescribed by the navigation rules. Maintaining course, maintaining speed, maintaining a lookout, taking action to avoid collision even if it involves departure from the navigation rules. There's a standing joke among maritime attorneys that an island would be apportioned some fault in a collision.
When the Coast Guard conducts investigations, we don't even assign fault. We find facts and measure them against the Navigation Rules.
Most road users do use the law to their advantage. It tends to make for good order.
