No but if she says the Conservatives have cancelled it for the day and the other parties don't they'll get crucified by the right wing press (particularly print).
So you are buggered if you do respond and buggered if you don't.
UKIP have not cancelled campaigning...
UKIP are very right wing, are already villified by the left, and who rely on incidents like this for their conversions. They stand to lose nothing by doing so.
What a great way to make the radicals popular. They will certainly gain a lot by being the only ones disagreeing.
Sorry my words were not clear, glad someone else clarified for me :)