Read my earlier post. I don’t think the _ENV_G assignment happens when you
do a load (after all, this would have the effect of resetting _G after
every call to load()). My reading is that setting _G happens ONCE only for
the distinguished environment (when the Lua_State is initialized I
presume), and never again.
_G is only set if you load the base library into the Lua state, either
with luaopen_base() or luaL_openlibs(). Lua itself does not use _G as far
as I can see (checked both 5.1 and 5.2), and I suspect it's there just for
convenience.
-spc
