Not sure how it got a lock, perhaps it was firing in the simulation at nothing to just make it that bit more action
As for the video, really interesting to watch (especially as if I had a choice if I got in the RAF as a pilot I would want to fly the F-35). Is this going to be on the export versions as well (such as those to the UK) or not (or has it not been released yet). Suppose another question that comes to mind is can it be retrofitted to other 3rd/4th generation aircraft such as the F-16/F-18/Eurofighter (guess we don't know that yet).