You beat me to it, Watchbreath. Reminds me of a certain Seagull chrono movement (could it have been the ST1902?) that has a 'faux' hour counter. The hand is linked to the center hour hand and tracks with it.
However, it should be noted that with a certain failure modes of a 7750, the hour counter will run continuously.
Since the hour counter is run independently off the mainspring arbor, brake failure, or excessive drag in the clutch will allow the hour hand to run even with the chronograph shut off.