Televisionary: That's because your husband's right. (Pierce was probably, at the oldest, a toddler in 1959, when Rocky and His Friends debuted on ABC, and still couldn't have managed that voice two years later when it became The Bullwinkle Show on NBC.)
The narrator for the Rocky and Bullwinkle segments was William Conrad, who was probably best known as CBS's detective Frank Cannon on (what else?) Cannon , which ran from 1971-76. Before his moose-and-squirrel gig, he was the radio voice of Gunsmoke's Marshall Matt Dillon.
And before anyone asks, the narrator of the Bullwinkle "Fractured Fairy Tales" was Edward Everett Horton.