I have 40.68% mastery
Templar's Verdict hits target dummy for 84,126 (w/o Inquisition)
Hand of Light hits target dummy for 31111
This equals 36.98%
3.7% below what my mastery % states
Now with 40.68% mastery and the tool tip clearly stating additional damage AS HOLY DAMAGE, with Inquisition active (30% bonus to all holy damage) my actual hand of light proc should be around 53% of whatever my CS, TV, or HoW hit for. As per 40.68 * .3 = 12.02
12.02 + 40.68 = 52.7
Templar's verdict hits Target Dummy for 82,630 (with Inquisition)
Hand of Light hits target dummy for 41711
Not the 52.7% that would be expected.
I believe there is some kind of bug going on with Hand of Light.
Id like to add that this was on a lvl 90 dummy
Also I was in PvP gear so no set bonus of any kind relating to HoL.
And I tested this in 5.2 numerous times and it was working correctly at the time.
This is since 5.3 launch.