The Horrible Effect of Parry

[Skandranon]

Next question: Is this behaviour universal or limited to just Gruul? One combat log from a single encounter isn't conclusive evidence. (Unless this feature had been added recently I would have thought it would have been noticed much much earlier).

It applies to all parries by all entities, and has been known for at least a year (the behaviour was first documented in the early Naxx days). Players parrying get their attack speed increased, bosses parrying get their attack speed increased. It's why Parry rating has always cost more than Dodge rating (even in the earliest WoW 1.00, 1% parry clearly cost more than 1% dodge - see Hyzenthlei's original formulas).