On the ship travelling to the US from New Zealand Burt talks with the Maori men crew on the ship and calls them, good humouredly, monkeys.
This is no racist reference, it's a term that anyone of his age would have used for someone younger than them.
I do similar things, calling people young enough to be my children "kids" and "boys". I have also been known to call small kids, little urchins, monkeys, particularly when they're full of "beans" (energy), and running around, laughing and giggling.
Just don't let the self-appointed language watchdog Sam Watson get onto this or the movie will have to be redubbed because he will demand that people will be offended.