The original text has the archaic construction “did loose me not”. For the 1837 edition, Joseph Smith changed this awkward verb phrase to “did not loose me”. Elsewhere the Book of Mormon text has several examples of the simple past tense of the verb followed by not but without the auxiliary verb do, as in these examples involving me:
All these examples show a strong biblical context (scriptural quotation or Jesus speaking). This kind of archaic construction is, of course, quite frequent in the King James Bible.
These examples imply another possible kind of editing for 1 Nephi 18:13—namely, removing the auxiliary verb do to give “they loosed me not”. In any event, the original combined use of the auxiliary do with the negative adverb not after the main verb appears to be intended in 1 Nephi 18:13 and will therefore be restored in the critical text.
Summary: Restore the original word order in 1 Nephi 18:13: “they did loose me not”.