[Exim] filter: case unsensitive testing condition

As described in

http://www.exim.org/exim-html-4.30/doc/html/filter_toc.html#TOC43
This condition:
if "$h_to, $h_cc" contains freebsd@???
then
    save uafug
endif

have to be case unsensitive. But emails for freebsd@???
are not fall in condition.

Is it a bug?

PS exim 4.30, FreeBSD.
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Sem.