Schrödinger's Prime Minister

From The Metro:

THERESA MAY said she was too busy ‘talking to voters’ to take part in last night’s TV leaders’ debate... adding that she wanted to talk to the public. She said: ‘He ought to be paying a little more attention to thinking about Brexit negotiations. That’s what I’m doing.’

The third possibility is that was she busy talking to voters (from 8 'til 9 in the evening) while thinking about Brexit negotiations. And presumably you can talk to more voters by knocking on doors for two hours than by appearing on the telly, which is Diane Abbot style maths.