Like most films, they leave a lot of the story out to fit it in the time allowed. There is a lot more to the story of 'old Burt' than just the Indian (like when he cut a Triumph crank and camshaft, turned them 45 degrees and welded back together) and his Velocette. He did (I think from memory) something like 14 trips to the USA, not all with the Indian, that the movie condensed into one trip.
If you can get a copy of the book it is a good read.
'One good run' (the legend of Burt Munro) by Tim Hanna.
ISBN 0-14-301974-0
Published by Penguin Books.