I think think the reply you got was mostly talking about their marketing. The MSDS is a federally regulated document. The results are derived directly from analysis. There would be real world consequences if the MSDS was incorrect.
So, it does appear to have calcium from the MSDS that I pulled from Dr Earths website. 7%. I found it interesting that the values on the MSDS don't match the label. May they are just rounding down a bit? I suggest looking at the msds for all nutrients if they are available. Very informative.