Again, put yourself in the position of trying to ascertain if a person is coming to the US under false premises. You've determined they have. Now, at the border, under threat of deportation, you're going to say "OK, call this place and tell them no", and you're going to take that as an acceptable answer?
That idea just doesn't work. Worse, it creates more incentives for people to try to come under a false premise, as they can just backtrack at the border and still get in.
I wouldn't say this guy was here "for work" and I don't think he thought he was either. Hell, a different agent on a different day probably would have let him through.
There are better ways this could have been handled that wouldn't have led to deporting him.
If you take as a given that the US wants to enforce their immigration laws, allowing people to attempt to break the law with a penalty of them saying "ok just kidding" doesn't make much sense.
It's like the liquids ban at airports. If you ARE caught with liquids, there's no penalty, you just throw them away. So it's not a disincentive to try to bring liquids aboard. Just keep trying until it works.
Each achieves the goal of keeping their intended contraband out, why make a big deal out of it? The angry boneheads at the TSA are not responsible enough to teach behavior modification.
That idea just doesn't work. Worse, it creates more incentives for people to try to come under a false premise, as they can just backtrack at the border and still get in.
This case sounds mishandled, for sure.