This is more than a clerical error, it is disgraceful if you are fully aware...
Just out of curiosity - how are such thinkgs actually organised on the shop floor? Do the mechanics work off of the actual SB provided by the manufacturer? In that case - how could they have performed the procedure incorrectly nearly a 100 times? Or is the SB first converted into some kind of works order - so there will be a single person (i.e. point of failure) who interprets the SB and creates the works order in the shop floor management system (computer or paper based)?
In an ideal world I would of course expect some kind of an integrated system - so the engineer at the manufacturer defines the tasks to be performed for the SB and these are electronically transferred as task lists for the mechanics. I have, however, worked on a major SCM project for a company which is a key supplier for Boeing, Airbus and a few other military aerospace outfits - and I know that the integration of systems in this industry is decades behind the ones everyone else is using that ensure you can always get fresh eggs at your supermarket, a pickle in your cheeseburger or your particular size of trainer at the sports shop.