There are several problems with the modeling, if this is 3D. First, the 109s were Fs. Battle of Britain was well over by the time Fs entered service. Spit1s gave way to SpitIIs, and then SpitVs before 109Fs showed up (I think).
Second, they don't show the 109 nose, but you can clearly see it has high exhaust stacks, and a bumpy hood, almost like a late model Spitty has. 109s had inverted V engines, the exhaust stacks were low, and the hood was round and smooth on top.
Third, the spitfires had 2 radiators, indicating later models (Spit9, I think, had those first?). They are, however, painted as BOB era spit1s, and the gunfire sounds like light MGs and the damage seems to support this fact. EDIT: There was also no evidence of cannon barrels on the wing leading edges.
I don't think it was very realistic either. Most fights weren't at sea level, and the events in the film are not realistic in my humble opinion. However I'll limit myself to the modeling errors.