I do not know what you would think that. A crc32 will miss an error if and only if crc32(error-pattern)=0, which happens in 1:2^32, assuming a full-cycle polyn

I do not know what you would think that. A crc32 will miss an error if and only if crc32(error-pattern)=0, which happens in 1:2^32, assuming a full-cycle polynomial. While these patterns are easy to characterize, and are independent of the data (neither is true for a crypto hash), the probabilities are the same.