If this night's an outlier, I wouldn't worry too much about it. The nasty cluster happens in the first hour after going to bed and it may be that restlessness and transition to sleep problems is causing the machine to misinterpret wakeful breathing patterns as sleep disordered breathing.
But if this kind of thing is happening on a lot of nights, then there may be a clinically significant problem with the transition to sleep. And that means contacting the sleep doc's office and letting them know what you're worried about.
Finally: The AHI graph in SH simply measures the total number of apneas + hypopneas scored in the last 60 minutes of the current session. It will reset to 0 when you turn the machine off and back on. If you don't reset the machine, it will take a full hour of event-free run-time before this graph will return to 0. ResScan has a similar graph, but the ResScan graph resets to 0 at the top of every hour---even if you're in the middle of a nasty cluster of events.