''Your critical strikes cause the opponent to bleed, dealing 60% of your melee weapon's average damage over 12sec.''
This doesn't specifically mention melee critical strikes, but all critical strikes.
I wouldn't mention this but I played only rogue on live and I explicitly remember losing duels/arenas because I got 12s deep wounds applied while kiting warrior.
Deeps wounds get applied after ranged critical strikes in Wotlk too.
Deep Wounds damage has never stacked in TBC, it's always been weak in overall damage because it merely refreshes and loses most of the damage. Where in the video do you figure you're seeing a 3k deep wounds tick?