Reading Salah fast
In the name of Allah, the most Beneficent, the most Merciful.
To read the Holy Qur’an quickly or hastily in such a way which leads to the improper pronunciation of certain words are severely disliked and if it changed the meaning of the Holy Qur’an, it will break the salah. It is because of the aforementioned reasons that “Shabeena” (completing the Holy Qur’an in one night) is considered impermissible. (Fatawa Rahimiyah p.387 v.4)
As the Imam was leading a quiet prayer in Zuhr you should not have any doubts or misgivings whether the Imam has read the Holy Qur’an hastily or not.
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham