Hypertoxicity doesn't work with caltrops sometimes

[cypherusuh]

I'm not sure if its a bug, but currently, it doesn't apply the feat correctly.
if you throw Poison Throwing Knife regardless of type, it'll refresh any poison currently applied to the enemies with Hypertoxicity, making it very hard VS very high DT/DR enemies.

[Styg]

I don't get it. Could you elaborate a bit?