I certainly understand the treble damages issue, and you can be guaranteed that the lawsuit discovery process will dig for any evidence of that. Nonetheless, you can imagine that they might have quietly taken a look and plotted a strategy in advance.

Once documents start hitting the courts, we'll know more about the case's back-story. This will be fun to watch. At the end of the day, the worst thing that's going to happen is that Nest ends up paying a royalty of some undetermined amount to Honeywell. I'd be quite surprised if Honeywell manages to get an injunction to force them to stop selling their product.