In the name of Allah, the most compassionate, the most merciful
As a general Islamic rule of Salah (prayer), there are some conditions which can invalidate your Salah (prayer). One of them is relevant to the PRONUNCIATION. In other word, it is said that in case that your pronunciation is not true (which changes the meaning), as a consequence it would invalidate your Salah or Namaz.
For instance, as you gave the following example:
When I am supposed to say:
"sub hana rabb ial 'ala"
it comes out like:
"sup hana rapial 'ala"
It looks wrong, since it has change the correct word to the wrong word of "sup hana rapial 'ala”. In the meanwhile, to the best of my knowledge, at least at majority of times it can change the meaning.
But, may be mis-pronunciation in Mustahab parts of Salah such as Qunoot doesn't invalidate that.
And Allah knows best