The only mentions I can find refer to "support materials" for assisting clients - That could broadly mean everything from documentation to firmware (which they hold on to tightly with cold, dead hands). Rimini's website seems to suggest they were probably accessing everything.
The fact that they were making money off it - and ignored a request to stop - is probably the main difference between this and going after open-source projects. Its essentially taking customers away from Oracle's own support services.
Supposedly they had a contract for support purposes; but whether Oracle intended for wholesale copying and redistribution (if that is even what happened,) is an exercise for contract nitpicking - obviously this is all speculation [[ stares longingly into the vacuum that was Groklaw... ]]
It could have come down to simply an aggressive/abusive crawler affecting other customers?
The fact that they were making money off it - and ignored a request to stop - is probably the main difference between this and going after open-source projects. Its essentially taking customers away from Oracle's own support services.