Power Trip

I put my lunchtime soup into the microwave today and when I removed it, it was barely warm. That was when I noticed there were no lights on the microwave. I checked the clock on the oven and it was out as well. 
The Residual Current Device (Earth Leakage Trip) had gone. It reset fine.

I hadn't noticed it trip as I was using my laptop at the time and it just carried on with its battery. 

Now the question is what caused it to trip? The microwave is favourite as it was the only device pulling any amount of power at the time, but there are any number of other little things around that were plugged in that could have caused it. Only time will tell.

At least with most devices either having built in batteries to maintain the clock, or auto resetting from phone networks, DAB radio signals or NTP I only had 2 clocks to reset, the oven and the microwave.