just curious, some of you might have an interesting point of view/insight

Back in the day I heard a radio interview with Randy California and he acknowledged the similarities but had absolutely no interest in pursuing it.

Zep Rep: "Yep, We're Pepped"

They should have played the jury an excerpt of "Black Mountainside" alongside Bert Janch's earlier "Blackwaterside" just to give them an idea of how likely they were to plagiarize one of their songs.

Just knowing/proven how talented Zep's songwriting abilities are/were, there's really is no need for them to plagiarize (especially during the early 70's). On their very 1st album, Zep remade a lot of old blues songs and gave credit to the artist.  
Now if Milli Vanilli had gone & done this......oh wait......that was just a faulty CD......NVM. 

Mesh
Just knowing/proven how talented Zep's songwriting abilities are/were, there's really is no need for them to plagiarize (especially during the early 70's). On their very 1st album, Zep remade a lot of old blues songs and gave credit to the artist.  
 

...or not... Much of the 'credit' was given way after the fact, such as the Jake Holmes song 'Dazed and Confused', which took an out of court settlement a few years ago. 'How Many More Times' steals from more than one song, and Sharke is right about Jansch's 'Blackwaterside' being lifted almost note for note (and title).

I can go back for decades and give a better case that the group's song they are saying was stolen by Led was a copy of at lease 10 songs. MY Funny Valentine for one. This suit is ridiculous and shouldn't have ever been in court. I Am waiting for some corporation to declare they own Am!

The riff was too close to be a coincidence. However, there is no way the song was a 'copy'. Perhaps Zep should have payed something akin to a sampling use type license.
 
It does seem a bit sleazy for the estate to be trying to get a payday now.

Didn't know that James, and I see what you mean....

There should be a time limit on these types of complaints. In this case it sounds like people who have done nothing want to make money of of people that have. If it was genuine, this should have hit the courts in the 1970's. There's only a handful of notes to work with and millions of compositions. What's the odds that you don't play an arpeggiated minor chord that somebody else played first?

well, I personally think that jimmy might have been inspired by the melody or concept having heard it- but beyond that, no. 
I also believe that it was entirely up to randy to pursue the issue in a timely manner after stairway was released- his failure to do and the subsequent passage of time amounts to a forfeiture imho.