See, what's a "fluke" and what's a "problem"?
My personal opinion is that in the US, the number of crappy drivers is about equal to the number of people who use car seats wrong. Most are unintentional. Some are intentional (of which I admit to not being an ideal driver, and also that I do it knowingly). Plus, I used to work as a DA in traffic court. I've talked to countless drivers and read tons of accident reports and then talked to various parties and their own versions of what happened.
Depending on a numerous number of variables, including road condition, traffic, condition of the tires, etc, when you resume cruise control (or even without pushing any buttons), cruise can go faster than you intended. It's not exactly a sophisticated system.
Now, based on those two stories in the article, you've got an unintended acceleration of about 15 mph. That's on the higher end of what I've seen, but not too ridiculous (particularly in CA).
Now, it's entirely possible these people knew exactly how fast they were going. However, considering that most people have an insanely inflated opinion of their driving skills, combined with a national tendency to never accept any personal blame, along with the known fact that people under stress often can only focus on a limited number of things, let's just say I'm taking their numbers with a large grain of salt. Assuming the true story is somewhere in the middle, let's cut that number in half (and that's being overly generous IMO). That puts it at about 7-9 mph faster than expected. Totally reasonable due to "normal" factors based on my personal experience.
The article on the cruise control problem is nearly worthless. Combined with the relatively tiny number of cases out there, along with the fact that the Prius, being a hybrid, has a markedly different driving experience than "normal" cars (thus throwing off people even more in them thinking things are weird when they're actually normal for a hybrid), and I think the cruise control thing is a non-issue.
I'm more interested in the pedal problem cuz I think there might be something there. However, there just isn't any good info out there. Might never be.