TLR was the 3rd nail in the coffin.
Not going balls to the wall for Harper/Wheeler the 2nd.
Ultimately, with hindsight though, the moment in time where it all went to s%*# was when whoever made the decision to deprioritize player development and ALL Latin American spending except for Cuba. Even if it wasn't a conscious decision, nowhere in basically 20 years did someone stand up and say "We suck at this and need to do whatever it takes to get better"... Which seems to be right around after they won the World Series and stopped producing their own Magglios, Carlos Lee's, Credes, Rowands, etc.
Not supplementing this core we had with our own well developed players doomed this "rebuild" and is the primary reason this franchise has not been competitive at all since 2008, with the 2nd factor being never going after premium talent.
It all starts at the top.