If reports are correct, they baited the lion to leave a known restrictive area.
When you are on safari, you know what you are allowed to kill.
He went and killed the lion they showed him. I doubt very much he knew that PETA revered the lion. Upon questioning, the locals and the government had no clue about it.
Baiting is not selective. If the lion left the preserve, do you suppose their intent was to kill this particular lion?
You usually get the information from your guide, if the guide is not trustworthy... I have no idea if he knew what was going on, but that is something we should know before judging him.
I have heard many stories of hunting guides in the U.S. taking hunters into areas they were not allowed to hunt; National Parks, Indian Reservations, closed hunting areas, and private land without permission.
When you are on safari, you know what you are allowed to kill.
I wonder why people pay for guides, then.