Many British bureaucrats had already packed up and left ahead of their official departure on May 15. But the Jewish state couldn't be declared yet.
Normal governmental functions still needed to be done. And who did them?
The Jews, of course.
Palestine Post, May 3, 1948:
May 4:
This is leadership.
The wealthy Arabs ran away in December, but their political leaders in Jaffa and Haifa were the first to leave, not the last, when those cities were taken over by the Haganah. (May 4)
And what about in the Arab sector? They were busy doing a run on their banks (May 2):