@GroundedSpanner
Very clearly you have never ever dealt with ILFC. I have.
If anyone, THEY are in the aircraft business, more so than many of the airlines. The A330 design owes its final form (and success) to Steven Udvar-Hazy who told them that they either build it to his specs, or he will not buy any. They were elbow deep in the 787/350 design process as well, being one of the largest customers for aircraft manufacturers.
ILFC would have supervised that repair very carefully, more so than the operating airline. That being said, flaws can remain no matter how carefully the repair was planned and supervised.