Thanking Hashem for being saved from sakanah – great
Thanking Hashem by ignoring the existing sakanah – bizayon and Hillul Hashem
When it is a mixed bag – is it a hetzi-full or a hetzi-empty kos bracha?
as this is a safek – I advise you to say hetzi-hallel bli bracha
frankly, it is more half-matza, half-hametz