The Boeing 777-300ER was designed and built in the early 2000s, long before Boeing had its current quality issues. From the "I'm not saying this happened" statement, it sounds like the person who died didn't have a properly fastened seat belt.
Fuck Boeing for many reasons but I don't expect them to control the weather ahead of their flights. I don't get any indication from the article that there was any incompetence involved unless I missed something.