Koopman is the real deal. Big fan of the RTX-2000 here, and his embedded software book is excellent. But my recollection is that he and Barr found no such particular bit - the argument was, if one task failed, which could be due to any number of potential bugs, perhaps just one bit getting flipped, the unintended acceleration could happen.
The material from Barr is worth reading too (google it), and if you want some amusement: