While I cannot
validate the second part of the
write-up, I can say that it is possible. What is being described is a
reflex phenomenon, a basic
stimulus-response mechanism.
For example, when the doctor taps your tendon below your patella during a physical, it sends a signal to the lumbar section of your spinal cord, which gives an automatic feedback to kick your leg up. Never is any signal involved in this route directly sent to the brain.
Roaches have extensive nerve systems, as I remember from the roach dissection in Bio 1A, in addition to having really small brains. It would not be a stretch to assume that this is the mechanism that evolved in cockroaches to escape predators and danger over millions of years.