وَإِنِ انْتَفَخَتْ أَوْ تَفَسَّخَتْ: أَعَادُوا صَلَاةَ ثَلَاثَةِ أَيَّامٍ وَلَيَالِيهَا فِي قَوْلِ أَبِي حَنِيفَةَ رَحِمَهُ اللهُ، وَقَالَ أَبُو يُوسُفَ وَمُحَمَّدٌ رَحِمَهُمَا اللهُ: لَيْسَ عَلَيْهِمْ إِعَادَةُ شَيْءٍ حَتَّى يَتَحَقَّقُوا مَتَى وَقَعَتْ
Translation: If the carcass has swollen or decomposed, Abu Hanifa requires repeating three days and nights of prayers. Abu Yusuf and Muhammad hold that no prayer must be repeated until the time when it fell in is established.
The two views differ on evidentiary standards: Abu Hanifa treats decomposition as an indicator supporting a longer retrospective estimate; the companions do not invalidate prior prayers without establishing the time of contamination.