I don't think so. That's the opposite of what he said (changing the decimal point from "." to ","), and it's the opposite of what his code does.
I see what you mean, but it still make no sense since he says setlocale works.
$ perl -we'use POSIX; setlocale LC_NUMERIC, "fr_FR"; print 0+"123,45"' Argument "123,45" isn't numeric in addition (+) at -e line 1. 123