The OP's code even does what you've said "many people" do. Using the & prefix to call a sub disables prototype checking. The combination of both &sub and prototypes should be a red flag (in addition to each being a red flag in and of themselves).

I second that thoroughly. And it was very good of you to underline this sort of "synergy", because I didn't. Actually since there are prototypes, this may be one situation in which &sub may have sense, to overcome them. But it does not have sense to overcome them, so just as in the vast majority of cases, it's not needed and better avoided, period.