If I move the die() out of the DESTROY, this becomes a non-question don't you think?

If you don't, then your question is a non-question. ("How do you make Perl not act like Perl?")

The whole point is to figure out why perl thinks we are cleaning up (even though we are in the middle of runtime),

It is cleaning up an object, and you're wrong in thinking Perl think it's in the global destruction phase.

$ perl -wE'
   DESTROY { die "foo" }
   { bless({}) }
'
        (in cleanup) foo at -e line 2.

$ perl -wE'
   DESTROY { die "foo" }
   our $o = bless({});
'
        (in cleanup) foo at -e line 2 during global destruction.
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