sng big stack play

so I'm in an SNG right now; big stack with 10K in chips went all-in 6 hands in a row (blinds, 200/400; four players left), just daring us to call him.
key hand: UTG raised to 800; I folded AJs; SB (chip leader) went all-in; BB folded; UTG called all-in for his last 2K. UTG with KQo, SB with 33.
The flop didn't help anyone; turn was a blank; King on the river.
Chip leader down to 8K, he's slowed down since!