It would be more appropriate to die on error, and expect the calling code to trap it using:

eval { 
    # calls go here
};
if ($@) {
    # exception handling here
}
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I tend to save die's for outside of classes. You die and someone doesn't handle it, they get screwed over. At least with an undef, scripts may be able to run to completion... depending on how you code it.
Humma la beeba la seeba la booba la
Humma la beeba la seeba la bop

People who don't read the documentation (or ignore it) deserve their problems.