Plus it's an opening statement. It's an intro that tells the finder of fact (traditionally a jury, but for cases like this it's the judge) what evidence you're going to present during the trial. You want that person to be able to place that argument in context, but the very nature of explaining that "I'm going to show you a bunch of stuff" is going to have a bunch of "well I haven't seen it yet, so can you tell me what to expect" responses.

Especially if there's a discussion of the different contractual relationships and the different companies and products. I've seen plenty of judges insist on clarity when communicating about things that might have more than one meaning: a company that has the same name as a product that company produces (Toyota makes Toyotas), a legal entity that has the same name as a place (Madison Square Garden banned someone from Madison Square Garden), etc.

For all we know, the confusion might be one of the lawyer's fault, for using the words Mozilla or Firefox interchangeably, the way this article seems to.

I think its also important to note, he was not explicitly unclear about what Firefox was, he was unclear about what Mozilla was. It's admittedly still not great, but I think it's a little more understandable a thing to be unfamiliar with than the browser itself. I'd really rather the title referred to Mozilla because of this, as really there's little to definitively back up its claim that the judge is unfamiliar with Firefox, just that he is to some degree unfamiliar with the company that makes it. Again, still far from ideal, but not nearly as egregious as they're trying to make it sound.