I was fortunate to view this incident as live just north of 24R/06L centre line, must have been very scary for those on-board. I was just straightening living room curtains when noted several extremely loud bangs which sounded like a large dumper truck full of stone on speed bumps. I realised this was the engine surging as I had seen this on Discovery channel when they first tested the GE engines for the 777 on the 747 test bed. Pilot(s) levelled out immediately at about 1500' and it was very noticeable that thrust had been increased on Port RB211.
An immediate shallow left turn was initiated.
Glad everything worked out fine.
Incident handled very profesionally by all of the team on board.
Funnily I have noted several Herons recently in the area.....