That is a good question.
The answer could be the following. A cuti-patisandhi moment is defined as a change in bhava.
- There are only three categories of bhava: kama bhava (including all 11 realsm in kama loka: four apayas, human realm, and the six Deva realms), rupa bhava (20 rupavacara Brahma realms), and arupa bhava (4 arupavacara Brahma realms). See “Bhava Sutta (SN 45. 164).”
- In both of the above cases, there was no change change in bhava. Both the animal realms and the Deva realms are within the kama bhava. Also, see “Gati Sutta (AN 9.68).”
The critical point is that both animals’ gati changed momentarily, and before the gati changed back to their original “animal gati” they died, and the gandhabba that came out with the new gati instantly transformed to match the “better gati” prevailing that that moment.
- Even though anyone’s gati can change like that, the physical body prevents the gandhabba from transforming to acquire the new gati. But if the gandhabba comes out (due to the physical body being dead), it will instantly transform according to the gati at the moment.
