I haven't, but that doesn't mean it couldn't happen. I would be very surprised if happens more than once in a blue moon (you'd hear about it here on the Disboard if it did happen), so I wouldn't hold much hope that it would happen on your night/day.
The person who made the ADR at 5:55 am seems like the time is within the differences between clocks. Meaning, the Disney system might think it's 6:00 am, and the person on the computers clock might say 5:55 am. The 15 minute difference is a little less likely to be due to clock differences, but still possible.