Q. Do the acts of disobedience (i.e. sins) which a Hajj pilgrim commits, diminish the reward of the Hajj?

 A. Acts of disobedience in general diminish the reward of Hajj, according to the Words of Allâh, the Most High:

فَمَن فَرَضَ فِيهِنَّ الْحَجَّ فَلاَ رَفَثَ وَلاَ فُسُوقَ وَلاَ جِدَالَ فِي الْحَجِّ

“So, whoever intends to perform Hajj therein (by assuming Ihram), then he should not have sexual relations (with his wife), nor commit sin, nor dispute unjustly during the Hajj.” [Al-Baqarah 2:197]

Indeed, some of the scholars say that acts of disobedience in Hajj invalidate the Hajj, because he is forbidden to do them in Hajj. But the majority of scholars hold to their well known rule, which is that as long as the unlawful act is not specifically related to worship, it does not invalidate the Hajj. Acts of disobedience are not specifically related to Ihram, since acts of disobedience are unlawful in Ihram and out of lhram. This is the correct opinion, that these acts of disobedience do not invalidate the Hajj, but they diminish its reward

[Fatawa Arkanul-Islam by Shaykh Salih Al-‘Uthaymeen, Fatawa on Hajj (Pilgrimage), Q538 p.774-775, Darussalam]