I'm willing to bet you just startled him. If it were a feeder bite, you might actually be bleeding.
I got 'clipped' by one of my BPs after I had a brain fart on feeding day. While only her upper right jaw cut into my finger, I had blood trickling down to my wrist, and I'd compare this to being cut by glass.
Defensive bites are more like be savagely attacked...
With velcro.
On another note, I'm only unofficially in the bite club because despite getting tagged I-don't-know-how-many-times, I haven't taken a single picture. :/