Man arrested for trying to detonate what he thought was a car bomb in Oklahoma

The FBI seems to have gone further than usual (in my limited understanding of what is usual) here with "assisting" the man to incriminate himself. To me (not a lawyer) it sounds a little like entrapment.

  ... an undercover FBI agent posed as a person who could assist him.
  According to the complaint, Varnell took a series of actions to
  advance his plot. He identified BancFirst as the target, prepared a
  statement to be posted on social media after the explosion, helped
  assemble the device, helped load it into what he believed was a
  stolen van, drove the van by himself from El Reno to BancFirst in
  downtown Oklahoma City, and dialed a number on a cellular telephone
  that he believed would trigger the explosion.
  
  Varnell is charged with attempting to use explosives to destroy a
  building in interstate commerce.