regardless wether he should open with shield lob or not,

I've encountered countless idiots who prefer to go nuts on mobs as i'm still pulling. Making them get hate and make me either walk back get hate or just ignore it as i usually do for the rest of the fight.
There is a difference in hitting the mob or putting your debuffs on and then going banana's untill you get hate and move on to the next mob, all while i'm still pulling more.

I'm fine with people hitting the mobs as long as they watch their aggro. if i see they're hitting the mobs i'll often shield lob that mob an extra time but some people just do it to annoy you it seems.