I'll add on that this is an absurd lawsuit, in a music theory perspective. However, my legal knowledge is shabby.

Are there any precedents regarding cases like these? If, for some peculiar reason, Radiohead wins this case, then I can imagine they'll have the ability to just sue anyone that becomes popular that uses a similar chord progression / melody. Considering that "original music" is almost non-existent in pop music, what's going to happen then?