Zeppelin Prevails....

devoid of context, i agree with the verdict--the use of the four chord progression isn't so close  as to constitute a flagrant, my sweet lord-type ripoff (altho if you read the appellate decision it's based on technical rules of evidence rather than a comparison of the tunes themselves). however, zep are the most notorious music thieves in the annals of history, often lifting whole tunes from their blues or folkie authors without attribution, so my sympathies remain with the plaintiff.