All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
There are two dissolutions in Hajj: first dissolution which takes place by hurling Jamrat Al-‘Aqabah according to some scholars, or by doing two of three rituals: hurling the Jamraat, shaving or shortening the hair and Tawaaf according to the majority of scholars. By the first dissolution, everything becomes lawful for the pilgrim in the state of Ihraam except sexual relations.
By the second dissolution, everything becomes lawful for the pilgrim even intercourse with his wife. Ash-Sheeraazi said:
There are two opinions regarding activities which become lawful by the first and second dissolution. The first opinion, which is the sound one, says that all violations of Ihraam become lawful by the first dissolution except intercourse, and by the second dissolution intercourse becomes lawful. This is based on the Hadeeth of ‘Aa’ishah .
By the Hadeeth of ‘Aa’ishah, he means the Hadeeth which reads: "If you hurled the Jamraat, everything becomes lawful to you except women, perfume and hunting the game." [An-Nasaa’i and Ibn Maajah] [An-Nawawi: Jayyid chain of narrators]
The pilgrim who is required to slaughter an animal for ignoring an obligatory ritual of Hajj or doing one of the violations of Ihraam, this will not affect ending his Ihraam. However, it is obligatory for him to slaughter the Hady as soon as possible to free himself of liability. Dissolution of his Ihraam is valid and he is allowed to do everything lawful for the pilgrim who ended his Ihraam. The Hady that ending Ihraam is based on and cannot be valid before slaughtering is the Hady which is obligatory for the pilgrim who is prevented from completing his rituals. Allaah The Almighty Says (what means): {But if you are prevented, then [offer] what can be obtained with ease of sacrificial animals. And do not shave your heads until the sacrificial animal has reached its place of slaughter.} [Quran 2:196] This is different from all the cases in which slaughtering is obligatory.
Allaah Knows best.