The final sentence of this exercise is "To escape the penalty two of the generals …
The key gives:
δύο μὲν οὖν τῶν στρατηγῶν ἵνα τὸ δίκην διδόναι ἐκφύγωσιν
The special vocabulary glosses the penalty as τὸ δίκας διδόναι, presumably an articular infinitive.
I wondered why the change from acc pl to sing between the gloss and the key. I see that Plato uses the singular in Gorgias and thus am at a loss to explain why N&H gloss the plural.