Fang Zheng cheerfully took his Fleet Girl to dig the Forerunner's grave, completely unaware that his appearance had stirred up a storm within the UNSC.
After obtaining the Recombination Device, Fang Zheng simply took off, however, the unfortunate Chief Officer lacked his skills and could only stay at the Space Station awaiting support. Like all movie and game plots, the UNSC fleet arrived slowly, only after everything had ended, and by the time they got there, both the Forerunner and Fang Zheng were nowhere to be seen.
But that's not the main point. The important part is that the footage of Fang Zheng's Sea Mist Fleet fighting against the Forerunner and the Star Alliance Coalition was completely captured by the Space Station. After viewing these images, the leading UNSC officer was astonished and immediately reported the incident to UNSC headquarters, then took the Chief Officer and the Space Station director back to the main facility for questioning and investigation.