In his editing for the 1837 edition, Joseph Smith here removed the occurrence of and he after the parenthetical clause “and the law could have no hold upon him”. But in marking up 𝓟 for that edition, Joseph crossed out only the redundant he. He probably also intended to delete the Hebraisticlike and but just neglected to do so. The entire and he was omitted in the 1837 edition itself.
Similar uses of the connective and with a redundant subject pronoun can be found elsewhere in the original text, as in the following example that the 1830 typesetter removed from the text:
The critical text will, of course, restore instances of pronominal redundancy and the Hebrew-like connective and in the original text. Such constructs provide narrative cohesion in the text. Also see under 2 Nephi 10:3 for another example where the 1830 typesetter removed a redundant that he (which also follows a parenthetical clause).
Summary: In accord with the reading of the manuscripts, restore in Alma 30:12 the redundant connective and he; there is evidence elsewhere in the text for such usage.