Given the imprecision of WWII-era anti-aircraft guns it's a reasonable assumption.
You also have to make some assumption about the initial distribution of the hits in order to do an analysis of survivorship bias.
I have no problem with making assumptions but it would hopefully be grounded in a domain specific understanding.
If you read some of the replies, you’ll see one of the fixes involved fighter escorts. This is probably based on an assumption that fighters contributed to the downing of aircraft. These would probably have a different shot distribution than anti aircraft artillery.
Not to belabor the point, but jumping to conclusions on assumptions is exactly what good root cause analysis guards us against. A random distribution may be reasonable for an uninitiated statistician but I’m not sure one with some domain background in the problem would make the same assumptions.
I’m not sure a statistician would make that assumption. I’ve only heard this story told in the context of survivorship bias, not root cause analysis
Edit: I don’t mind the downvotes but please help contribute to the discussion by explaining what is disagreed with