According to this letter, if you enter Indonesia on a free tourist visa, you have to exit from an airport which offers free visas. Not all airports or ports of entry offer the free visa on arrival.
Bali for example offers the free tourist visa, but Lombok does not. So you cannot enter Bali and leave via Lombok if you got the free visa.
Your letters: On visa on arrival | The Jakarta Post
Bali for example offers the free tourist visa, but Lombok does not. So you cannot enter Bali and leave via Lombok if you got the free visa.
Your letters: On visa on arrival | The Jakarta Post