Ok I have had a paladin for very long and all I can say that this is veeeeery far from an exploit. Might help only FOTM rerollers. This has been working with exorcism proccing vindication on undead mobs for ages and its the same now.
This is how it is intended to work - every damaging ability can and most likely will proc Vindication (Read the talent tooltips when you roll a class for God's sake).
This belongs in guide section at best.