I suspect that this is caused by Template Toolkit using eq when an == is found in the document. This causes 3 == '03' to evaluate as false and violates the DWIM principle.

Well, this is an example of what Dominus talks about in the docs to his module Text::Template. Basically, why use a limited, somewhat different mini-language of Perl when you already know Perl? That is, unless you enjoy remembering a new set of quirks, exceptions and limitations.