Some observations:
I have watched movements on FR24 prior to this incident. Runway change took place just after midnight (local time), about 1 hr and 15 mins prior to EVA15's departure. During all this time every southerly departure turned right onto 090 followed by a further right turn heading 180. There were no left (all the way around) vectors for any previous departures. Furthermore with the ACA departing off 06R it is incomprehensible that EVA would have been given a deliberate clearance to turn left all the way around as this would have immediately created a conflict with ACA (as it in fact transpired).
So, again it comes down to the unheard (by us) initial tx by the controller. And indeed, as mentioned by Uplinker, the EVA initially turned left and flew on a heading of approximately 018. So, did they hear "left heading 180" and, instead of confirming with ATC, put the emphasis on left and decided "oh she must mean 018"? Who knows?
The official transcript will in time shed more light. What was said on the F/D will also be of interest, but that will probably never be known.