The irony is that Led Zep has put their names on others' songs more than anyone else I can think of--they happened to be mostly in the right in this case.  But "Dazed and Confused" is unbelievably blatant--far worse than Harrison/My Sweet Lord.
Any court that refuses to think Stairway to Heaven isn't largely derived (a euphemism for blatantly copied) from Taurus from Spirit shouldn't be allowed to make legal decisions on musical cases.