While I can quite rightly be accused of pre judging the outcome, I expect it will eventually turn out to be a software related fault.
Thankfully the F-35 only has 8.5 million lines of code in its software - what could possibly go wrong.....
I once knew a FJ mate who, when being shown over a couple of the latest generation of fast jets, only ever asked the manufactures rep one question, and that was? Whether or not the bang seat sequence was hard wired, purely mechanical and totally independent of any software!