What are the odds...?

[Wayward]

That a level 60 Bard, who's been on the Green server for 4 or 5 years, and is geared to the teeth with God / NToV / City Leader loot, doesn't know what constitutes a swarm?

Short backstory:

Bard in City of Mist, powerleveling a cleric bot for their guild. Bard is gathering about a dozen or more mobs from the 2nd and 3rd floor and using PBAoE DoT spells to damage them down all at once. However, not doing it in the safe area at Arena, the Bard seemed to have some trouble, causing mobs to fall off the upper floors and train groups down below on the 1st level, and also dying and causing the mobs pathing back to train groups on the 2nd floor.

When confronted with the fact that City of Mist is off-limits to swarms, for the very reason that the Bard is demonstrating, their response(s):

"I'm not swarming, I'm only collecting 10-12 mobs."
"I thought a swarm was uncontrolled mobs."
"Show me where in the rules it says what constitutes a swarm."
"Your definition of a swarm means nothing."

And the icing on the cake, the backhanded "apology":
"I'm sorry that the way I'm playing is upsetting you."

So RnF : in your estimation, what are the percentage based odds that this level 60 Bard, a longtime member of one of the Green server's foremost raiding guilds never learned what a swarm is? 0%? -10%? Nil?

Bonus points if you can guess the player.
Not as many bonus points if you can guess the guild tag.