With the deaths of Max Bygraves (Coach Guard) and John Forrest (Flashman) in 2012, all of the credited cast in this film have now passed away.
The production needed a number of extras for the rugby matches and the crowd scenes. As these scenes were filmed during the school summer holidays in 1950, the majority of the boys seen were not pupils at the school but locals to the area. Some of the crowd seen in long-shots were girls dressed in boys' clothing. They were contacted through youth clubs and local boy scout networks and paid 10 shillings per day of filming.
The second film with Robert Newton and John Howard Davies, a few years after they made "Oliver Twist" (1948).
When Flashman goes into the river and the three boys try to rescue him, there is real fear in the boys faces and at some points they really struggle in the water.