Differential AggroFollow

I helped a friend do the Antonican Creature Catalog the other day with his dwarf paladin. I was amazed as mob after mob he got within catalogging range without getting aggro. Timberclaws, Sogbones, Octopus, Kodiak, etc, etc.

I did this myself yesterday on a character a couple of levels higher - a Kerra mage this time. Every mob aggroed while I was still getting "too far away" on the catalog button. With a bit of sprinting I manage to get away from most but the difference was very apparent.

Anyone else noticing this kind of difference in aggro?