It's up to the authority.
Qantas have never said they did the inspections before the big bang, just that they were compliant.
In this case EASA specified that engines having done more than 250 cycles had to be inspected within 150 cycles.
That's a LONG time for an A380. See Table 1 at the bottom of the AD:
http://www.channel4.com/media/c4-new...0-0008R1_1.pdf