Bomber shld be harder to shot down. The fact that one wing fell of after being hit seems totally out of proportion with machine guns and 20mm canons.
You see fighter loosing their wings on gun-cam as munitions casing are hit by the bullet and explode (especially wing mounted canon shells). Bomber, especially British bomber) had flexible wing tank (sometime made out of leather and rubber like protective cover) and then don't explode when hit. They burst in to flames (orange ball of fire is OK) but with no destructive shock waves. However has the fire spread rapidly, the aluminium (or even faster with wings made out of wood) melts and there is rapidly a wing structural failure.
So IMOHO wing hit, ball of fire, fire spreading and then 1 min to ten mins latter wing ply.
Anyway, it's always sad to see that Wellingtons boxes are far easier to down than a single Blenheim

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