I believe your assumption that he's lying. This won't be something new in our world :)
However, I don't see that you talked to him about this.
To you, it looks like inferior work ethics: It looks like he's trying to do nothing and still get paid.
To him, it's a last ditch attempt to keep his job: he's way over his head in this task. If he actually didn't care about this, he'd have admitted this is beyond his current skills and let the managers asses if he's salvageable as an employee or needs to find another job.
I actually think he cares about this job and this task very much. Maybe too much, that he's willing to make moral compromises and put himself in a "double or nothing" situation.
Why don't you bring this up to him, don't judge or patronize - just help him get it running and once everyone's happy, let him know you'll be there for him next time too (of course, that's just to encourage him to raise his hand nice and early, instead of "buying time" and risking a big disappointment).
To be honest, people who will bite more than they can chew and lie about it, tend to be a liability. However, if they are taught to be more open and cooperative, their willingness to take charge pays off!