• na aham pratīcche — I do not want (anything in exchange)
  Prati-√iṣ (to desire in return). The original owner refuses any substitute; only the specific cow he owned would satisfy him. Brāhmaṇa-property is not fungible — that is the lesson the verb is teaching.
• apākramat — went away
  Apa-ā-√kram (to step away). Both brāhmaṇas exit the negotiation. The poet uses two different verbs for the two exits (apākramat / yayau) — the symmetry is deliberate. There will be no settlement at any price.
• ayutam icchāmi — I want ten thousand (more)
  Ayuta (ten thousand) + icchāmi (I want). Spoken with the preceding 'na' / 'na anyat' (not even...) — the second brāhmaṇa refuses any inflation of the ransom. Together the two refusals prove that the offence is structural — it lives in what the cow is, not in how much can be paid for her.
• aparaḥ yayau — the other left
  Yayau, perfect of √yā (to go). The second brāhmaṇa's leave is final. With both gone, the case is closed in this world and opens in Yamarāja's. The next verse will carry Nṛga south.

• Where am I still trying to fix what the other person has refused to let me fix?
• How do I sit with the consequences of a refusal I did not engineer?

Two brāhmaṇas refuse a kingdom's worth of cows because neither wants what is wrong — and in their refusal seal the king's fate. Sometimes the most pious response of the offended is to walk away, not because they are cruel but because they will not participate in a wrong settlement.