When one says something is ḥalāl and another says something is ḥarām.

" And when Mūsá returned to his people angry he said, "What an evil way you have differed from me in my absence..." (Sūrah al-Aʿrāf, v.150)

"And indeed We gave the Children of Israel the Scripture, and the understanding of the Scripture and its laws, and the Prophethood; and provided them with good things, and preferred them above the ʿĀlamīn (mankind and jinns) (of their time, during that period), and gave them clear proofs in matters [by revealing to them the Tawrāt (Torah)]. And they differed not until after the knowledge came to them, through envy among themselves. Verily, Your Lord will judge between them on the Day of Resurrection about that wherein they used to differ." (Sūrah al-Jāthiyah,v.17)

"And remember when Allāh said to Īsá, 'Verily I am going to take you and raise you up to me and purify you from those people who have disbelieved and, make those who followed you truly above those who have disbelieved until the day of judgement, and then i am going to return you and judge between all of you in the matters which you used to differ about.'" (Sūrah Āl ʿImrān, v.55)

When the prophet ¸ل الله عليه وسلم came and started to call to the worship on one deity, worship to Allāh alone and to stop acts of worship dedicated to other than Allāh he was blamed for making Ikhtilāf, splitting families. This was a clashing/blameworthy Ikhtilāf, however in this Ikhtilāf the people upon the haqq are not to be blamed, those who oppose the haqq are to blamed.

"And we have not sent down this book to you except that you clarify to them the affair they have differed over."

"Those who have differed about the book are far off in opposition" ( Sūrah al-Baqarah, v.176)

"And do not be like those who have split up and differed after clear guidance has come to them. They are the ones who will have a great punishment" (Sūrah Āli ʿImrān, v.105)