[anthk]

The same in Spanish. Steal a hen, get a harsh sentence. Steal millions, you are now a respectable 'businessman'.

[atrocious]

The law locks up the man or woman Who steals the goose from off the common But leaves the greater villain loose Who steals the common from off the goose.

[Gibbon1]

Kill a man you're a murderer. Kill millions and you're a statesman.

[moomin]

Pretty sure that’s known as The Blair Doctrine.

[appreciatorBus]

Or the Stalin doctrine, "One death is a tragedy, a million deaths a statistic"

[pezezin]

I am Spanish and I have never heard this proverb...