[Sonata Theory] 26p: Dominant seventh in the V:HC MC

Related text in original book: 26p
"Additionally, within the first-level default in either major-mode or minor-mode expositions one occasionally finds a seventh included in the V chord at the MC point. This seventh is best regarded as a passing tone. In the first movement of Haydn's Symphony No. 100 in G ("Military"), for example, the structural V/V, the half cadence proper, is articulated at the downbeat of m. 62, after which it is prolonged. During this prolongation the seventh is added (entering fist in mm. 64-65, though most prominently in mm. 69-73), suggesting a V8-7 figure. The seventh (^4 of the new key) resolves to an inner-voice ^3 at the onset of S (m. 75)."
This video is only for my personal study, and may contain some error.