The author writes:
5/69: Saabbi’uuna should be Sabi’iina. (= Sabians)
i.e. he wants صابئین instead of صابئون in the following verse:
إِنَّ الَّذِينَ آمَنُوا وَالَّذِينَ هَادُوا وَ الصَّابِئُونَ وَالنَّصَارَى مَنْ آمَنَ بِاللهِ وَالْيَوْمِ الْآخِرِ وَعَمِلَ صَالِحًا فَلَا خَوْفٌ عَلَيْهِمْ وَلَا هُمْ يَحْزَنُونَ
This, again, is not a mistake of Quran. Instead, the author is not aware of a style of Arabic language. Sometimes things are understood in the text and the case of a noun is decided according to that. We mentioned one of such understood subjects in our last response. A similar understood plays here due to which the word is in nominative case. You can find the examples of this style in Arabic corpus. For example, a poet writes:
فمن يك أمسى بالمدينة رحله… فإني وَ قَيَّارٌ بها لغريب
See قَيَّارٌ is also in nominative case here even though it should have been in accusative case because coordinating conjunction وَ dictates that إن should affect it as well. But the effect is not there. Similar is case with صابئون i.e. the particle إِن of إِن الذين آمنوا didn’t affect it. So, it is not an error rather use of a different style. The grammarians call it عطف علی محل i.e. considering the subject of إِن as an independent subject the second subject is joined to it by a coordinating conjunction.
In our opinion, this is another style of نصب علی الاختصاص. Since all the nouns in the verse were already in accusative case, to highlight the word, it was changed to nominative case. Therefore, it will convey stress. This is akin to making a portion of text bold or italic in modern writings. In other words, difference in cases served as a ‘bolding’ tool. Keeping this in mind the verse will mean: Jews, Christians and the Believers will definitely find salvation and if Sabians also fulfilled this condition they shall, too, be rescued. In this matter there is no difference between them and the other three sects.
Please note that there are 3 more opinions regarding this style which we are leaving unattended.