Augustine's Miaphysite Theology

Leporius' Amendment

In the Statement of Amendment written by Leporius, signed by Augustine and others, we read a multitude of things which are very Obviously Miaphysite. 
We read the following:
“And thus God ‘the Word’ Himself receiving everything that belongs to man, is made man, and the manhood which is assumed, receiving everything that belongs to God cannot be God; but whereas He is said to be incarnate and unmixed, we must not hold that there is any diminution of His (singular) substance..”
[Leporius; Statement of Amendment, signed by St. Augustine, Bishop of Hippo] Although the Dyophysites can argue that perhaps it was translated poorly or even a mistake done by the scribes, it is made clear that there is a nature which is compounded out of two later on:

“For it was not God the Father who was made man, nor the Holy Ghost, but the Only Begotten of the Father; and so we must hold that there is one Person of the Flesh and the Word: So as faithfully and without any doubt to believe that one and the same Son of God, who can never be divided existing twin substance (a substance of two) who was also spoken of as a ‘giant’ in the days of His Flesh truly took upon Him all that belongs to man, and ever truly had as His own what belongs to God: since even though He was crucified in weakness, yet He liveth by the power of God.”

[Leporius; Statement of Amendment, signed by St. Augustine, Bishop of Hippo] Historical Context

For background, Leporius had fallen into a type of Nestorianism:
“The idea of a clear distinction between the two natures in Christ and the reluctance to compare the peculiarities of human nature to God for fear of debasing the divine nature were conceptions remarkably similar to those that would emerge a decade later in the East in the preaching of Nestorius.”

[Irene Gobbi; Leporio – Un Caso di nestorianesimo prenestoriano]

Leporius constantly made the distinction between the Individual human nature and the Individual divine nature of the Word of God, and he later found refuge with Augustine, where he’d go on to repent from making these distinctions in the Statement of Amendment.
We can therefore affirm that St. Augustine of Hippo must have:

• Affirmed two natures being distinct was heretical

• Affirmed something other than two substances (One Substance or something else, but for the sake of affirming a “Twin Substance” we will say he affirmed One Substance)