First, a disclaimer: Theistic evolution (TE) is neither a theological system nor an alternative to mainstream evolutionary science. TE is an awkward label applied to people who accept evolutionary theory and also believe in God. Those who claim this label are not a unified group. The following is my own understanding, which is still evolving.
The early chapters of Genesis, taken as historical narrative, are impossible to reconcile with mainstream evolutionary biology. To accept evolution as fact is to deny Adam and Eve as history.
On the other hand, the typology of Adam and Eve does not change if they are not historical figures. If the story of Adam and Eve is allegory, then it is an allegory explaining the beginnings of God's relationship with created beings.
Put into a framework of hominid evolution, Adam and Eve represent the first beings capable of living in relationship with God. This is represented by God's breathing the "breath of life" (Genesis 2:7) into them.
The eating of the forbidden fruit that "opened their eyes" (Genesis 3:7) is a poetic reference to the awakening that transformed amoral hominids into moral agents, capable of distinguishing right from wrong.
And I don't think it's much of a stretch to suggest that this moral awakening grew directly out of an experience (or multiple experiences) of realizing the consequences of wrong actions. That's one of the lessons of Adam and Eve: actions have consequences.
So, no TE does not necessarily deny Adam's fall as being representative of the entire human race. In fact, from a TE perspective we could say Adam's fall is nothing other than representative of the entire human race.
And in answer to the question in the title, the "alleged evolutinary animal/ape/man" became accountable for his sins when he first became aware that he was acting against the will of God.