I found this article from "Business Hungary" about the Mangalitsa. Click on the images to view it.
The article says that Toth was an agricultural engineer who saved the pig. My understanding has always been that it was done with the assistance of the Olmos family. I say that because of articles like this one.
I'm guessing the article doesn't mention the Spanish connection because the article appeared in "Business Hungary" (not "Business Spain"). It sounds a lot more romantic to say Toth did it alone - but as the article itself mentions, the Mangalitsa wouldn't have thrived the way it has if were strictly a Hungarian phenomenon.
In any case, if the Mangalitsa could have survived as a strictly Hungarian phenomenon, they wouldn't have needed Toth; whoever was producing the pigs in Hungary would have kept on doing it and it would have been self-stustaining.
Obviously the Mangalitsa costs too much for Hungarian consumers (then and now) to support its production. So even if Toth had come in, gathered the pigs and produced them, without the Olmos group to help him turn those pigs into money when they were done, he'd have been stuck with a mountain of Mangalitsa inventory, and that would have been it.
Looking at it cynically, the ability to pass off Mangalitsa as Iberico probably increases the chances of the breed surviving; so long as Spain remains an expensive place to raise pigs, there ought to be demand for Mangalitsa.