Certainly the Indo-European root of the modern word "man" comes from the Sanskrit "manu", although I thought "manus" was Latin for hand.
Not really sure what Mike was on about, but "man" and all the "manu"s do not trace to the same source at all. "Man" enters the language from the Germanic, while all the hand business is, indeed, Latin. The Indo-European roots are similar, but they're not identical.