I think bonking while riding long distances is fatal. You tend to move around, disoriented, less alert, like a drunk. Makes it easier to crash into things, like trees and cars moving at high speeds...

It happened to me the first time I rode almost 40 miles in one go. Not enough fuel (energy bars/carbohydrate calories) left me milling around the MUP, swerving everywhere like a drunk. I nearly crashed into some club riders , fell off the bike, back into the street, when I maneuvered it onto the sidewalk , and nearly collapsed from exhaustion by the time I got home from the ride.