[Jaepa]

Maybe; They should have still been able to file amicus curiae but likely they would have to appeal the remedy instead of attempting to become a co-defendant.

The case was Google illegally using it monopoly power. The Remedy was to prevent some of the anti-compitive actions. If the agreement was to split up Google, or for it to sell off chrome it wouldn't make sense for Apple to be a co-defendent.

[wbl]

IANAL but AFAIK amicus curiae is not for "my interests will be impacted in this case because I have a claim that's involved". It's more for things like "hey, we do a lot in this area of law and here's something neither party has thought of that your decision might impact".