sure, <an unseen flaw in design or materials> can manifest itself
anywhere, but everything is modeled and tested beforehand-
didn't any pedal stickiness or stiffness show up anywhere ? frankly,
I suspect someone saw it and hid it; someone shrugged their
shoulders and figured that to go back and re-engineer the
assembly wasn't worth it....
It's likely that the models worked on paper, and that prototypes
passed mechanical tests for everything they could imagine, but
they failed to imagine everything.
Whatever the ultimate resolution of the pedal problem is ,
the fly-by-wire gas pedal will always be unsafe compared to
a mechanical cable. Each electrical/electronic component
in the engine control chain ( sensors, computers, controllers,
relays, switches) has its own set of failure modes, and serial
failure probabilities multiply each other. It is suicidal to
add another electronic failure multiplier at the gas pedal,
further risking engine runaway, while at the same time taking
away the mechanical cable assembly that would at least have
let you save your own life by slamming the throttle closed.
The Amish and the Luddites didn't get everything wrong.