Yes, but I don't think it scales with things such as pvp power and mastery, this debuff is quite old.
The Rogue must've been pushing how about of spell power at the cost of his agi in order to hit big numbers.
At the same time the debuff effects varies to everyone. If you read carefully what I said 5k to 55k max, the only instance of the debuff critting that high was on retail and other pservers, as for this Rogue or any other Rogue they'd be pushing between 8k to 45k. At the same time it depends on how said class use it and how much they're willing to sacrifice of their stats to hit harder. Now with high crit the damage is increased and ot effects different targets differently.
The pandaren said it best himself when he explained the poison, for its effects can be modified to, I can't question him because he knows how to use it. At the time 90s couldn't get it essily until Warmane changed the resillince. At the time he was helping said community become better in BG (not 90s bg).
I'd like to add this is one of several hidden debuffs/buffs in the game, up to this xpac as well, still retaining their vanilla style actions.