The mistakes’ author writes:

63/10: ‘akun should be ‘akuuna

His objection is on the following verse:

وَأَنفِقُوا مِن مَّا رَزَقْنَاكُم مِّن قَبْلِ أَن يَأْتِيَ أَحَدَكُمُ الْمَوْتُ فَيَقُولَ رَبِّ لَوْلَا أَخَّرْتَنِي إِلَىٰ أَجَلٍ قَرِيبٍ فَأَصَّدَّقَ وَ أَكُن مِّنَ الصَّالِحِينَ

This is not a mistake of Quran but that of author. His grasp of the linguistic styles of Arabic is pathetic! If it were أکون it would have meant that the coordinating conjunction وَ is joining it with the word أَصَّدَّقَ. This would have implied a secondary position for it i.e. ‘After giving in charity, I would have become a righteous guy, too’. But now it is directly joined to the grammatical placement of أَصَّدَّقَ which implies that both أَصَّدَّقَ and أَكُن are desirable at the same time i.e. ‘I would have given in charity as well as become a righteous guy’. This style is called عطف علی المحل which, we believe, has also been discussed at some other place.