Xerox’s suit was dismissed because they took too long to file it. Apple was suing MS at the time and if Xerox sued Apple and won then both Apple and MS would have been liable to Xerox. Interesting enough is that Apple didn’t win the “look and feel” lawsuit against MS. Except for one tiny thing, the trash icon.
Xerox's suit was filed and then DROPPED by a CEO who was unaware of the agreements that resulted in the Apple visits. Xerox dropped the suit when Apple presented the agreements SIGNED by the previous CEO in its answer to the suit, showing no tortuous conduct took place. They also pointed out the statute of limitations had long since passed, but that was secondary to their primary point.
Apple did not win the Microsoft suit because a judge ruled that a very poorly worded contract that Apple's John Sculley thought limited a use license of their GUI to only Windows version 1, actually was unlimited, and threw out all of Apple's infringement claims based on that contract's wording! There actually were about seven things.