WotLK Low xp gain after mob is killed by another person

[nuklear]

Hi, got a problem. I was getting boosted by my friend's 80 and i stopped getting normal ammount of xp (ex. on 5 lvl - i got about 500 xp, then on 7 lvl when I hit the mob first and he finished it i got like 48 xp - we were not it the party). Any ideas how to fix it?

[Shred]

It's done on purpose.

[nuklear]

It's done on purpose.

I mean I understand it. But why doesnt it work from the beginning then? Thx for the reply anyway