While we are talking about hate.
Please keep in mind that over the time effect (DoT and Regen-type spell) will get (a little bit of) hate each time they proc.
for example an ARC that like to put poison arrow on all the mob at the start of the fight will probably not pull hate "at the moment" they fire the skill but if the tank doesn't generate more hate on the sub-mob after the first flash and just do combo, the ARC will have a surprise 12-15 second later, since the poison arrow will have proc'ed a couple of time since.