Not that I support this in any way, but I can't quite comprehend the technical ignorance in legal circles that has lead them to distinguish between streaming and downloading in the first place.
The definition of downloading was written into law before streaming became widespread; likely, when the former was used to prosecute someone for streaming copyrighted material, the defense pointed out the inadequacy of the existing definition. There's a distinction in law between downloading in the sense of saving something to your hard disk and just having it in RAM. Obviously, if I go to your website and see something on my screen, I have 'downloaded' in some fashion, but if just passing through memory was considered a download then running a program or opening a file would be considered equivalent to making a copy.