Regardless of which version of the facts you consider more believable, the public was scared witless of the possibility that there was an exposure. As a result millions of people were left with the concern that they could get cancer decades down the road. This public fear is also the most important impact of a dirty nuclear bomb used as a terrorist weapon. Very few of people will get sick, and fewer still will die. But lots will be scared.
> Regardless of which version of the facts you consider more believable,
Believable has nothing to do with it. An average dose of worst case 1000 times higher, 1.4 REM, doesn't even violate the US federal annual dose limits. Attempting to equivocate this with dirty bombs is either ignorant or a malicious, inflammatory lie to generate fear for an ulterior motive.
If you're trying to insinuate some kind of cover-up, the did a pretty terrible job because no new reactors came online after TMI for like 50 years.