When the soldiers storm the hill, who are they shooting at? The only person there is in clear view and taking no cover.
Firing an automatic weapon creates intense heat on the barrel so firing one from the hip without a thick asbestos glove (or engineered hand guards) would burn the shooters hand. However, this is a Lewis gun that has an air-cooled barrel with a shroud and aluminum fins inside acting as heat sinks.
Using a Lewis gun Tom mows down many mounted soldiers, but no horses are injured.
A Coca Cola sign is seen in the background during the bank robbery. The design is from a more modern period (1940s, rather than 1915).