the ambiguity inheres in whether the word "Author" refers to the author of the Anacreontic Song, or merely to the author of the Fifth Book of Canzonets; see Lichtenwanger (1977), pp. 13–15
Lichtenwanger (1977), p. 15: "[Library of Congress music librarian Richard S. Hill (1901–1961)] did not accept the alleged claim of the Fifth Book, nor did he believe that any composer alive could have failed to identify himself at some point with a tune that became so popular in Britain and America, latterly in a way completely unforeseen. Not finding any evidence for ... anyone else in the picture, Hill concluded by elimination that Tomlinson must have put his words to a melody that already existed. Because of the tune's considerable dependence on the tonic triad—which, for example, supplies fourteen out of the first seventeen notes in the modern "Star-Spangled Banner" version—Hill wondered whether the tune had not come from military music, where trumpets and horns at that time were still limited by the lack of valves and pistons to the natural overtone series in which they do not achieve all the tones of the diatonic scale until they reach up almost to the height of "the rocket's red glare." With much help in Britain and America, Hill searched a large part of the pre-1775 tune repertory; but, as with Kidson and Sonneck, no prototype was found. Hill was tantalized by a bandsman's book in the Sutro Library of San Francisco that contains the Anacreontic tune captioned "Royal Inniskilling." He could show that the book had once belonged to a musician in the band of the Sixth Enniskillen Dragoons (the Irish and the colloquial English spellings are different). An Irish correspondent swore that his mother always said that the "'Royal Inniskilling' was mother to 'The Star-Spangled Banner.'" But Hill could find no evidence of the tune's existence under this title before 1799. He was too sound a scholar to publish without conclusive evidence, and during that impasse he tragically died."
According to [1]: "Sic evitabile fulmen roughly translates to "this repels thunderbolts" (It was a common Roman belief that laurel provided protection from lightning.)
