no i totally see where you are coming from, i do. i can see how someone inexperienced would easily be tricked by people too.
But this guy IS experienced. theres no way he was just sold a bad bill of goods. He knew the people to see to hunt a lion illegally, at least how the evidence is stacking up.
Im obviously by no means some poaching expert, i have SOME (little) knowledge of hunting practices, but i know you cant just show up in Zimbabwe and start asking the locals "hey which way is lions?!" and then after getting it thought "HMM WHATS THIS COLLAR BETTER BREAK IT". they also specifically lured the lion off protected grounds, again, something someone with his experience would know is just not something you do.
the guy is an experienced big game hunter. he either knew he was being set up and didnt care, or wasnt set up at all and planned to illegally hunt a lion, IMO.