There's some pretty unhelpful posts here. What good does public lynching do?
There are many worrying questions that result from this incident however. Mx staff not understanding procedures and terminology, no monitoring/check of work done, competency questions, haste in getting the job done without checking if its correct first, flight crews not logging previous issues and hence lack of investigation/follow-up... yes the engineer is responsible but the wider procedural, competency and quality procedures raise many more worrying questions and there are clearly gaping holes here.
Thankfully a good ending this time but it could easily have been very different. I hope lessons are not just learned but acted upon to stop this happening again.