An awful lot of motorcyclists zip out to the left without a second look too.
In their case they'd be dead wrong, but I've been able to slam on the brakes and let them so far.
Sure I could protect my right of way, but not at all costs.
Which gets back to the original comments by Summerfield. She looked. She looked. Saw nothing. What if the reason she saw nothing was because the rider did in fact dart to the left from a place out of Summerfield's line of sight, say from behind other traffic, and at a speed that would not be reasonably expected by anyone in the traffic flow at that given moment.
If so, why would Summerfield feel any need to apologize for having done everything right only to have that effort thwarted by someone who may travelling at a speed completely unreasonable in respect to that of other traffic on the highway. Her words - "he FLASHED by" says a lot more than some here sem to want to acknowledge.