The security researcher quoted in the article agree with you:

  > Arbor researcher Marc Eisenbarth said there's no evidence
  > Healthcare.gov has withstood any significant denial-of-service
  > attacks since going live last month. He also said the 
  > limited request rate, the lack of significant
  > distribution, and other features of the tool's underlying 
  > code made it unlikely that it could play a significant 
  > role in taking down the site.

Although, I will say that if the tool is grabbing the dependencies of each page (which in total comes to about a megabyte per page load), it might add up over time. Yeah, it's static, and yeah, it's not LOIC (it'd surprise me if LIOC weren't also being used against this site), but the site debs didn't do themselves any favors with the size and number of their static assets.