Thats a pretty simple melody in the Satch/Coldplay case. Seems to be a very unfortunate coincidence for Coldplay. It's a shame they've probably already made assloads more money off that melody than Satriani figuratively speaking, but I highly doubt they heard the Satch song and purposely borrowed it. Still, I can see Satriani's motives for the lawsuit.
It's funny how after hearing the main kick pattern on Meshuggah's "Bleed", I'm hearing it in different places as well, like the new Gojira album and the latest Textures album. I even wrote a song a few years back with an almost identical pattern, albeit minus a kick hit and with way less repetitions. Simple things are easily "shared" by coincidence.