No trinket proc, ye,thats weird.
Lava burst is like 65-80k without trinket proc
I mean, maybe he was lucky with procs
2x 80k lava burst
2x lava burst mastery
Fulmination crit
Ill rewatch vid later, cant remember the numbers, but i wont lie thats weird, but can be super lucky
Edit:
Out from what I saw, it looks just really weird. Not sure what it is, but I don't remember doing 60% of someones health in 5.4 (5.3 yes, but not 5.4).