Which particular Prime Minister would Gromit be referring to?
If it's the Prime Minister of Pakistan, Yousaf Raza Gillani hasn't 'scarpered' anyway. He's working hard to find ways of dealing with his country's problems.
Meanwhile the President of Pakistan, Asif Ali Zardari, is concerning himself with more long-term issues, such as the fight against terrorism.
Which means that they're both carrying out their constitutional duties.
Chris
PS: I also think that it's completely pointless for any political leader to visit the scene of any disaster. In these days of electronic communications, anything that a political leader can do can be done from anywhere in the world but it might still be best if he simply stays in his own office, from where he has the quickest access to advisers who really know what's going on and, hopefully, also know how to deal with it.