I wouldn't have thought so, I presume the switch is on the brake pedal - so it's very unlikely they'll have been near it when doing discs & pads.
I'd place my money on the brake pedal switch,,, normally, wire insulation is quite good on modern cars,,, and the brake switch is a known faulty component on these cars,,, costs a few quids and ain't difficult if you're just a bit handy with tools,,, it's just behind the brake pedal so it's obvious to recognize you can't go wrong. You may need to remove some plastic covers to get there tho,,, a few screws, nothing serious.
I know they're not supposed to go on. I don't believe any bulbs are in the wrong way but I'll remove them all in the morning to make sureHey, the rear lights shouldn't go on! Have you got a bulb in the wrong way round which is shorting to the tail lights somehow?