two kinds of memory - amensia and H.M.

I thought this obituary on the legendary H.M. was pretty interesting in that way that things in the NY Times are Interesting. They mention "two kinds of memory" that people have, one associated with conscious name recall located in the hippocampus (which I guess is what H.M. lost) and another that allows subconscious, habitual memory that is dispersed through the brain. Sounds a bit like memory and retention to me ... Tell me why that couldn't be the case.