Explain lol

How did A10 Avarius Reassembled one shot my Jugg?

6 endurance charges.
3k life.
80 phys / 80 ele res.

No fort.

His cleave caught me out of a slam (slow attack). Didn't think anything of it. One shot.

I looked him up on poe.db and see that cleave (lvl 68) does 744 damage. Assuming more + crit that's nowhere near enough to one shot that jugg with 80% phys mitigation.

Anyone got any better take on this?

https://poedb.tw/us/Avarius%2C_Reassembled#AvariusReassembledAvariusCasticusWickerman