+1 that you were likely the victim of steam getting into the head of the unit and causing the electronics to malfunction.
The APC needs to be in a well ventilated area. You can't put it in the corner of your kitchen counter, with overhead cupboards and expect there to be enough ventilation to keep it cool.
Also, You didn't make any mention as to whether the vessel you're using is covered or not. Having a covered vessel, with a hole cut for the APC to slide through produces a much better experience - virtually no evaporation and it minimizes the potential for steam (but, again, you need to be in a well ventilated area). If you look down from the vents in the head of the unit, you'll see the exhaust vents for the APC - some moisture will escape through these vents as well.
I actually cooked my ribs at 145 (pork ribs) for about 36 hours. 176 sounds like it would produced a tougher result.
For future - if you have a similar circumstance, prepare an ice bath, flash cool the bag of food in the ice bath, then throw them in the fridge about 20-30 minutes later, so you can get back to bed. For most meats, you can stop and resume the cook fairly easily, with little impact to the end result.
Fingers crossed your APC is functioning ok after drying out!!!