There is not a double standard as that phrase is meant in the USA. You must remember that not every place on earth is America.
There are laws in African countries, and there are policies. It's easier to write a policy that allows exceptions, then to change the entire law. It's not America!
As a simple example; It's illegal to hunt with any weapon that holds more then one cartridge and discharges a bullet with each pull of the trigger. Hence there are no semi auto hunting arms allowed.
However the policy is a bit different. It allows the most famous Big Game rifle ever to be used, The Double rifle, also double barrel shotgun, revolvers, etc. They are not going to change this rule, but they can issue a policy that creates a workable solution. The Policy is also easily revoked in a time of war, or uprise because it is not a law.
There are game laws that also have additional policies to create a workable situation for the business of hunting and foreign hunters.
It's very common for people to travel abroad and automatically assume that every where else on earth has or should have the same laws, administration and enforcement as America. It's not the case at all. America has control of America, not any other country, or how they govern or how they enforce what they choose to.