Quoted from "EsxCape;547541"
We've mentioned the buffs from bloodthirsty blade and potws before... weak point strike is nearly the same. If you read the skill, it's guaranteed to cause x-amount% dps each time you use it. You'll notice that number is kind of low... at level 60 it's in the 200's, at level 70 it would probably be 300-something percent. Anyway, then you'll see it has a *chance* to add additional damage. In the 60's it's ~400% additional dps. In the 70's maybe 100% more than that. However, this chance of added damage is so slim that you can't rely on it. In other words, you can't look at weak point strike at think "Oh this is over 600% dps!" when really you'll only be getting half of that the majority of the time.
Crit is separate from that. So maybe you use weak point and it crits, but you don't trigger additional damage...then it's just a crit of the 200-300% dps. Another time maybe you use weak point and it does crit, and also you trigger additional damage...then it's a crit of the total possible dps (a crit of the 600+% dps). But when the chance to trigger the additional damage is so slim to begin with, the chance of it also being a critical hit is going to be nearly unheard of.
If the damage calculation server-side is somehow incorrect on top of that (as I think you may have suggested), then that further complicates things. xD