Bolivian president Evo Morales said in a news conference that he didn't know that LaMia had authorization nor that it was a Bolivian registered carrier, then a video shows him boarding the same plane 15 days earlier.
https://www.youtube.com/watch?v=g0yjUk3rM68
One thing to consider too is how up to date the owner operator was.
He had his crew flying the light weights, but when the chance of showing off his company was presented he sure did jumped into the left seat.
Landing in Bogotá was not an option for him, he knew that it will represent a delay of more than 3 hours at best.