Those numbers, i.e., 0.63 bound by 0.4 and 0.99 for age>65 group, must have been extracted from the Gaussian fit judging from the fact that different Confidence Level numbers are printed on the plots in page 32 through 37, meaning they are not flat distribution and majority of the data points are in the middle. For example, if you quote 99.9999% confidence level, everything will have points above 1 (dotted line) no matter what (with ignorable probability).
So, it is almost non-sense to call this data "marginal". I am not concerned at all.
BTW, I am a PhD physicist with good background on Statistical analysis, though it is not medical or biotech related.