Asia's guilds are already considered to be on a separate racecourse, so to speak, to the EU and NA guilds we habitually report on, thanks to their increased item levels and higher HP bosses, but this is far beyond that. Manaflask reports the following:
Apparently 七 煌 switched to 10 man after downing Lei Shen in 25 and that made all of Ra-Den's abilities work as it if were 10 man (except they had 25 people there fighting him) [...] The guild supposedly reported the issue to Blizzard so there isn't any actual exploiting going on, just a bug due to the different way in which 10s and 25s are handled in Asia (different lockout etc).
The guild have, as mentioned above, reported this to Blizzard, and are convinced that, given all the aforementioned, their kill shouldn't be considered valid. Ion Hazzikostas previously asserted that if he was badly bugged the limited attempts would be lifted, but that seems unlikely at this late stage. We will wait and see, but for now, he's down.