Official rationale for the difference stealing vs. infringing being file sharing if I recall the rationale correctly. Not the downloading of the product, the uploading of it to others. Again IIRC in the cases you cite they were fined for “downloading and sharing”. It may only have been a few bits of data, but any time you move from stealing to enabling others to steal, or from being a user to a dealer etc you are going to get hit with harsher penalties.
All that said, I think what happened to them was draconian as fuck, so please be aware while I understand the rationale for the penalty being set higher, I do not in any way agree with it being set at the currently absurd levels and the comparison you have there highlights how the penalties are way out of line.
In the end these types of lawsuits aren’t about damages, or some poor college kid downloading (or uploading) 30 songs. They are about generating fear in those who otherwise might consider using file sharing to get their movies and music for free. To that end, there has to be something to really fear.
And I’m off to watch my totally and completely legally obtained video file named “man of steel” which must be some kind of mistake obviously. 
