Hugo Achá was on the
list of persons allegedly targeted by the group.
If Achá himself was part of the plot, he and his right-wing "Human Rights Foundation" could have "investigated" the attack (like they "investigated" the Pando massacre) and blamed it on the Bolivian government.
Here is an interesting quote from July 2007:
"Morales needs time to repair MAS," said Hugo Acha, a prominent
opposition lawyer and television commentator.
"The assembly has failed as a point of understanding between the
Bolivian people. It's only dividing the country along regional and
ethnic fault lines," he said, comparing the situation to the
disintegration of the former Yugoslavia.
("Dispute over capital stymies socialist push", Washington Times, July 4, 2007)