Well, the way I read it, the problem wasn't that he choked storage with copies of the virus but that he screwed up in thinking that the phone system could handle all of these copies of the virus trying to make calls at once. He didn't realize the phone system was mechanical, for some reason, and couldn't handle a number of calls from a geometrically huge number of sources, all at once. Which is how the virus first got noticed. If I read the articles on the worm correctly.
But his mistake, in my opinion, wasn't writing the virus. I have to say and admit publicly, that I don't think RTM was ethically wrong in creating that hookworm and letting it free. See, he had already gone to people -- people in positions of authority -- who should have been more interested in what he was saying. And they failed to take much interest, and he was marginalized because of his efforts to do the right thing.
In the long run, we can measure the economic loss to the RTM worm in scant thousands of dollars in immediate cost. Projected costs, if we take into consideration that perhaps not being able to connect over the phone system to somebody in Massachusetts caused some broker to fuck up a $10,000,000 deal, we could add $10mil to it, but realistically it wasn't a huge fucking deal. Even calling it a m|stake begs qualification of the term, for the sake of clarifying the direction of the vector his mistake was scalar to.