Not too sure if we will ever be certain just who wrote what on BOB; Walton was always a lazy, slow-to-write composer who would have been delighted when his old friend Malcolm offered to assist in the orchestration, arranging,"touching up", conducting and even part-composing the score.

Originally just involved in the orchestration - as offered by Arnold - he later admitted, "and when William was stuck I helped him along." Arnold was also asked to extend the score (it was considered too short by UA, mainly for a soundtrack album they wanted to issue), and the last third of the "Battle in the Air" sequence is in his hand, not Walton's. Walton was heart-broken by the treatment received from UA, who decided on Goodwin to replace him, "music to give them a better rake-off", according to Arnold.

Walton and Arnold had been friends for many years (the latter had also completed the orchestration of Walton's String Quartet (into the Sonata for Strings, first recorded by Neville Marriner).