ἀλλὰ ... μὲν δὴ
cp. Soph. Trach. 627.
ἦλθε ... τάχ᾽ ἂν
, “might perhaps have come.” ἧλθεν ἂν
is a potential indicative, denoting for past time what ἔλθοι ἂν
denotes for future time. That is, as ἔλθοι ἂν
can mean, “it might
come,” so ἦλθεν ἂν
can mean, “it might have
come.” ἦλθεν ἂν
does not necessarily imply that the suggested possibility is contrary to fact; i.e., it does not necessarily imply, ἀλλ᾽ οὐκ ἦλθεν.
Cp. Dem. 37.57
“πῶς ἂν ὁ μὴ παρὼν ... ἐγώ τί σε ἠδίκησα;
” “how was I likely to do you any wrong?” [This was the view taken in my first edition. Goodwin, in the new ed. of his Moods and Tenses
（1889）, has illustrated the “potential” indicative with ἄν
（sect. 244）, and has also shown at length that ἦλθεν ἂν
does not necessarily imply the unreality of the supposition （sect. 412）. This answers the objection which led me, in a second edition, to suggest that ταχ᾽ ἂν
was here no more than τάχα,
and that the usage arose from an ellipse （ἦλθε, τάχα δ᾽ ἂν ἔλθοι）.
In Soph. OC 964 ff.
also I should now take ἦν ... τάχ᾽ ἂν
as = “perchance it may have been.”]