विपर्यये बाह्यकृतमुभयत उभयकृतम् ॥ कZ_०४.६.१७ ॥
viparyaye bāhyakṛtam; ubhayata ubhayakṛtam ।
In the reverse case it is an outside job; and when indications exist on both sides, it is done by both (insiders and outsiders together).
It provides a clear decision rule for classifying cases and allocating investigative focus (staff vs external suspects vs collusion).