Pet xp penalty

[contemptor]

I am PLing a friend, outside of group, and trying to avoid the XP penalty. My buddy is a chanter. Say he does 10% damage to a mob, his pet+DS does84%, and we let it die. I then finished the mob off at 6%.

My friend didn't get the XP. Why is that? It was green to me, so I don't know who got it. I only did 6% total, so I assumed my friend should get it.

Also, for the 50% rule. Does the pet's DS count as part its damage?