A Smooth Escape

Without taking time to retrieve his sword, “Ehud proceeded to go out through the air hole, but he closed the doors of the roof chamber behind him and locked them.

Judges 3:23,

What was “the air hole” through which Ehud left? “The precise meaning [of the Hebrew word] is unknown,” says one reference work, but “‘colonnade,’ ‘vestibule,’ have been suggested.” Did Ehud lock the doors on the inside and then leave by some other route? Or did he lock the doors on the outside with a key taken from the dead king?