About that oven knob: Is it located so that you could have reset it by brushing against
the oven while walking through the kitchen? Or might there be a safety feature that turns
the oven off if something is wrong with it? So many possibilities come to mind.
I could have indeed bumped the knob while putting the lasagne in the oven
It's a funny oven where all the knobs are on the front just above the griller instead of up high behind the hotplates. It's a fairly old oven by the looks of it, so no auto switch off feature. The oven door gets stuck sometimes too, it needs a good lubricant on the hinges.