Baiting lions is not illegal in Zimbabwe, or in most places lions are hunted.
I have not seen *any* reports that bait was used inside the preserve.
It appears the hunt was illegal, because there was no quota for a lion in the area, but baiting is a legal and ethical way to hunt lions.
The remains of Cecil, the 13-year-old dark-maned lion who had become a sort of rock star in Hwange national park were found in July of 2015.
He was allegedly baited out of the park so that he could be killed legally.
Legally, if, of course the land-owner, one Honest Ndlovu and the PH - Theo Bronkhurst - had a lion on quota or on licence.
(If they didn’t - which was the case - there is an unsavoury practice known as a “quota transfer” where an animal shot in an area without a quota is recorded as having been shot elsewhere and needless to say this is illegal and unethical in the extreme.)