I had a friend that had a Pit and in all honesty, that is the second only time I have ever been remotely afraid of a dog(first time was my buds Bouvier, he did NOT like men but LOVED women. A bit of a ladies man...). We were hanging out watching tv and he just started growling at me for no reason until my bud bopped him on the nose and told him "no", still have no idea what that dog had against me to this day. My dad's Robberman(half Dobberman-half Rottie) was afraid of my cousin one year at Thanksgiving to the point that she would cower next to me or my dad where she would watch my cousin like a hawk, no other festivity before or after has she displayed this pattern. Sometimes dogs do some strange things, I dunno as I don't claim to be an expert.