You find out ALOT later how he was planing to get away with it becouse honestly it's a terrible plan to so obviously be embezzle money.
TL
R if he had managed to take the money outside of the city the lord would not be able to accuse him off stealing the money Because of political reasons and personal connections of the family the fat guy belongs to. ( witch by the way is basically the lord's families arch rival, or at least his wife who have yet to show up in the manga)
So because Yuna made Cliff ( the lord ) aware of the problem much sooner than was expected (s he counted on the lord being busy with other things like the present to the king and so on )
He got caught before he was ready to skip town witch was his only real problem as if he managed to leave town he would have been scot-free.
Its kind of strange that they would hire a person with clear conections to what basically is the lord´s familys arch rivals....
But it likely was not planned to be like that when this first few chapters were written as this is only explained like six arcs later.
for context we are just about done with the second arc.