The issue itself is subject to appeal, and with so much at stake, it would be foolish (and send the wrong message) if TPL did not prepare an appeal and proceed accordingly. However, I would not read more into it than that. It is something they really must do, and so they are.

Appellate courts are an entirely different breed of animals from original tries of fact, and the question on appeal (in most instances) is not one of fact but proper application of the law at the lower level.

I do not practice patent law, and so perhaps someone who does can discuss the burden of proof  /  logistics of review in a Markman appeal.

tps