See LSJ ἂν with participles and infinitives.§ 24.1 Τὰ δὲ καὶ παρ' ἑτέρων ἂν λεχθέντα, ταῦτα προβαλεῖν ἡμᾶς ἀναγκαῖον ταῖς ἀπολογίαις.
But what others also might have said, we must anticipate in reply. A. Robertson 1891
Sentence starts with a hypothetical scenario represented by a substantive participle.
When looking for this in the New Testament but didn't find it.
§ 24.1 Τὰ δὲ καὶ παρ' ἑτέρων ἂν λεχθέντα, ταῦτα προβαλεῖν ἡμᾶς ἀναγκαῖον ταῖς ἀπολογίαις. Τάχα γὰρ ἄν τις εἴποι καὶ τοῦτο· Εἰ ἐπ' ὄψει πάντων καὶ ἐμμάρτυρον ἔδει γενέσθαι τὸν τούτου θάνατον, ἵνα καὶ ὁ τῆς ἀναστάσεως πιστευθῇ λόγος, ἔδει κἂν αὐτὸν ἑαυτῷ ἔνδοξον ἐπινοῆσαι θάνατον, ἵνα μόνον τὴν ἀτιμίαν τοῦ σταυροῦ φύγῃ.
But what others also might have said, we must anticipate in reply. For perhaps a man might say even as follows: If it was necessary for His death to take place before all, and with witnesses, that the story of His Resurrection also might be believed, it would have been better at any rate for Him to have devised for Himself a glorious death, if only to escape the ignominy of the Cross.
A. Robertson 1891