I'm guessing it means that it was Genes idea for the end of Down and Under, where it gets quiet, whereas the ending Devy had wasnt like that ... , Or perhaps he couldnt find an ending for the song that he liked so Gene saved the day ... ? And since he helped out, Devy was grateful and wanted to be sure to give him credit for it, in the thanks, because putting "Written and produced by Devin Townsend (except for the quiet part on the end of Down and Under by Gene Hoglan)" in the booklet would just look silly