Hunting Leopards

Hi All. You've read that I liked the book
"Maneaters of Kumoan and The Temple Tiger",
written by Jim Corbett. He writes about 2 leopards
that he shot, one in particular where he sat in a tree over a
live goat at a distance of 20feet and the leopard took
the goat. He then shot it with a DB 12gauge shotgun
using OObuck if my memory serves me right.
After reading and looking at video, the PH's stand off at
a distance of 40 or so paces in a blind.
Now my question is this; Could Corbett have shot the leopard
as he described?, considering how smart leopards are
(the one he shot killed over 400 people), and yet our experienced
PH's in Africa do it a different way.
Is there a difference in leopards in different countries (Corbett hunted
all his maneaters in India)?
I know from my limited experience, which is 5/10's to 3/4 of bugger
all, that leopards are very smart and highly deadly when wounded, but
are leopards hunted in a different way particular to the different
countries and environment? or is Corbett exaggerating for dramatic
effect?
I'd really like to know a bit more about these magnificent cats?