It would be a very interesting patent fight if Echostar were to perform the lunar flyby without licensing it from Boeing. How could Boeing possibly win damages? How could Boeing show they had damages? No product was imported into the US and it definitely happend outside the US.
If I remember correctly there was a recent case where someone was suing ATT for selling a product that violated US patents outside the US and the Supreme Court said tough luck to the patent holder since it was not in US jurisdiction.
Of course Dish does business with Boeing, there are other ways Boeing could fight back.
Only way I see the patent working is if you wanted to start a launch service that would put payloads into low earth orbit and use the moon to finish the job. And of course you launched them from the US.