Just finished a ride, during which I passed through a segment. When I finished that segment during the ride, my Edge 830 reported segment time of 0:53. I can open ride history on the Edge, find that ride and that segment, and it still shows "0:53".
Now, when I look at the list of segments for this ride in Garmin Web interface, it says that it took me "1:12.9 min" to ride the same segment. The difference is too large to be explained by any calculation errors. So, what is this nonsensical "1:12.9 min", where does it come from? What is going on here?