I agree — the aircraft stalled.
HST, I suspect the starboard engine lost power or failed. I have seen F-18s accelerate and climb almost vertically out of the “high alpha” flight condition at many airshows.
Compressor stall on starboard engine - the -404 will give about 32K pounds of thrust even on wet a/b - too low - too slow - too bad for the a/c
ACES saves another pilot....