It could be there was information that CRA was looking for from the doctors. It could be that incorrect boxes were ticked.
I agree with Kim that it does seem really strange that such a high number would be disallowed. If there are 2,300 adults being assessed every year, if this year was a typical example, or this eight-month period was a typical example, and 42% of them are being denied, that does seem like a very high rate of denial.
CRA likes to say their overall numbers for life-sustaining therapy have an 80% approval rate, which is a 20% denial rate, but if it's 42% for adults with type 1, that's concerning.