Lady’s Wrath talent rewards temporary health for melee kills.
Virtue of Knightly Temper talent instantly slays enemies with melee critical strikes.
However, when a melee kill results from a Virtue of Knightly Temper proc, the hero doesn’t get any THP.
Also happens sometimes with Blessed Blade ability kills. Probably when it crits?
Video demonstration: https://puu.sh/G13kP/552a45988e.mp4