Fear isn't required for an adrenalin response. I accidentally shocked myself with household 120V AC once (the back of my hand brushed up against a live exposed wire). My hand jerked away by reflex before I was even aware anything had happened. I did not experience any fear because the danger was already past before I was even aware there was any danger. I did, however, experience a strong adrenaline response immediately afterward. Granted, this is only anecdotal evidence, but it does suggest that adrenaline response without fear is possible even though it is generally the case that they occur concurrently.
