ORAC, I googled this line from the committee report - seems they bought Burbage's story on LO. Attention span couldn't handle reading the whole thing so I guess they may have qualified it later.
"We have been assured that the STOVL variant of the JSF aircraft being procured by the UK and US are identical and are being designed to the same set of requirements, though, once delivered, the aircraft will be fitted with different weapons. "
Don't disagree that Burbage can get a bit weaselly wordy at times. He was recently asked what the plan was if the UK left the program, his reply was he doesn't think about that. Right. Like he's running a $300b program and no fallback if UK waves bye bye.