Yes. These are complex issues.
We need to keep in mind that it was a Bodhisatta who gave that advice, not a Buddha.
The other thing to consider is the following.
– A society lives by certain laws. If murderers are not punished, they may commit more crimes.
– Noble Persons LIVE BY a different set of rules. Buddha did not obey those rules for HIMSELF. He saw that Angulimala had the wisdom to attain Nibbana and interfered while the King was getting ready to send an army to catch and kill him.
– On the other hand, Buddha did not try to interfere with the general laws of the society. It was legal to keep slaves at that time, and the Buddha did not try to change those laws. However, he freed some slaves (just by asking them to become bhikkhus) and the King did not interfere in such cases.