In terms of classical works (non-Greek papyri), Caragounis quotes what's supposed to be Plato's Politeia 329d, although I tried to confirm the passage, and could not find the exact words in the Republic (Politeia). But Caragounis asserts that Porter improperly translates this passage as "it is a narration of the things that have come about, that are and are intended" instead of "are to come/will come."
The problem reportedly arises when Porter attempts to treat the future as though it does not express future action:
"His eagerness to prove the thesis, that the future does not express future time, leads him to treat reference and meaning less carefully than desired" (Caragounis 327).
The next bit of Greek that Porter supposedly does not understand aright is Plato's Parmenides 141d-e. But Caragounis avers that the words really derive from Euripides' Troades 467-468. Now I had a much easier time finding the exact quote for these Euripidean sentiments:
ἐᾶτέ μ᾽ — οὔτοι φίλα τὰ μὴ φίλ᾽, ὦ κόραι —
κεῖσθαι πεσοῦσαν: πτωμάτων γὰρ ἄξια
πάσχω τε καὶ πέπονθα κἄτι πείσομαι.
(Taken from Gilbert Murray's Greek Text of 1913. See http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.01.0124%3Acard%3D462)
Porter renders part of this text: "I am suffering and I have suffered and I intend to suffer" (πάσχω τε καὶ πέπονθα κἄτι πείσομαι)
Caragounis proffers the rendition: "let me lie fallen (on the ground); the things that I suffer and have suffered and will yet suffer are only fit for corpses (i.e. those that lie down (fallen) on the ground)."
E. P. Coleridge translates these fateful words thus: "Leave me, my maidens—unwelcome service does not grow welcome—lying where I fell; my sufferings now, my troubles past, afflictions yet to come, all claim this lowly posture" (ἐᾶτέ μ᾽ — οὔτοι φίλα τὰ μὴ φίλ᾽, ὦ κόραι — κεῖσθαι πεσοῦσαν: πτωμάτων γὰρ ἄξια πάσχω τε καὶ πέπονθα κἄτι πείσομαι).
G. Theodoridis offers yet another way of treating the Greek: "The body knows its proper place. It is here, on the ground. Because of what I have suffered, because of what I am suffering and because of what I am about to suffer, this is its rightful place. O, Gods!"
Part of this whole debate seems to be muddled by the challenge of tracking down the correct references, but Caragounis probably raises a legitimate issue regarding Porter's handling of Troades 467-468.