Serious digging was needed because he does not have the source. Any devs could easily profile the game during loading and that sscanf or strlen would be at top
Maybe they saw sscanf and assumed it is normal that it takes time, but more likely there were so much stuff to do and somehow no one checked
I imagine that even if you were on the GTA team, you'd most likely think the long loading time was unavoidable due to some complexity you were not aware of.
Great work to solve it from outside of the company.