Maimonides Minute – Hilchot Kriat Shma 2:13-14 (Making a mistake during Kriat Shma)

If you are not sure whether or not you said Kriat Shma, the Rambam rules that you must say Shma again, along with its berachot. Doesn’t that violate the usual rule that one does not repeat berachot if one is in doubt whether he said them?