Miscellaneous: NPC Casters with infinite mana

[FireEmblem86]

I was fighting a Burynai Excavator today, and it cast Tainted Breath, Waking Sleep, Sicken, 3 Spirit Strikes, Tainted Breath, and then 4 more Spirit Strikes.

According to MQEmulator, Burynai Excavators of level 16 should have somewhere along the lines of 320 mana. However, all those spells would take more than 500. This isn't the first time I've run across a NPC chain casting even after they should be OOM.