Both 'victory' rolls in BoB movie were aileron rolls....although the sound effects fella seemed to put in a slow roll recording for the one in France 'cause his engine faultered from negative G fuel starvation half way round...which shouldn't happen for an aileron roll.
Aileron rolls being a tad harder to **** up at low level twould seem the logical choice for a young fighter tyro in a moment of relieved exuberance too....relieved 'cause there isn't, on this occasion, a equally young and relieved tyro doing an aileron roll over a French airfield in a ME109...at his expence.