Corbett did not 'voluntarily' leave India. Like many other British and presumably other nationality foreign landowners, the new Indian government confiscated their land holdings and refused citizenship to them. I remember reading the village where Corbett owned land petitioned for his land not to be confiscated but it was denied.

British officers and civil servants serving in India, often holiudayed on safari in East Africa. It is very possible Corbett did as well. Especially if he writes comments as described.

As he served in WW2 in France as also is mentioned above, not doubt he travelled to other places, not detailed in his 'maneater' books. I'll have to dig out his biography to re-read again one day.