There was an ancient commentator called Zoilus who criticised Homer and had the nickname Ὁμηρομάστιξ or Homer whipper. Walter Leaf whose commentary can be found on the Perseus web site quotes a scholiast who gives Zoilus’ comments on this passage.
ἔνθ᾽ αὖ Τυδεΐδῃ Διομήδεϊ Παλλὰς Ἀθήνη
δῶκε μένος καὶ θάρσος, ἵν᾽ ἔκδηλος μετὰ πᾶσιν
Ἀργείοισι γένοιτο ἰδὲ κλέος ἐσθλὸν ἄροιτο:
δαῖέ οἱ ἐκ κόρυθός τε καὶ ἀσπίδος ἀκάματον πῦρ
ἀστέρ᾽ ὀπωρινῷ ἐναλίγκιον, ὅς τε μάλιστα
λαμπρὸν παμφαίνῃσι λελουμένος ὠκεανοῖο:
τοῖόν οἱ πῦρ δαῖεν ἀπὸ κρατός τε καὶ ὤμων,
Then Pallas Athene gave strength and courage to Diomedes, the son of Tydeus, to make him stand out among all the Argives and so that he he could win great glory. She made unquenchable fire blaze from his shield like the late summer star (Sirius) which shines very bright when it has bathed in the ocean and she made such a fire blaze from his head and shoulders,
From Walter Leaf’s commentary.
“Schol. A on this line is interesting as giving one of the few extant specimens of the method of Zoïlos, the famous “Ὁμηρομάστιξ — “Ζωΐλος ὁ Ἐφέσιος κατηγορεῖ τοῦ τόπου τούτου, καὶ μέμφεται τῶι ποιητῆι ὅτι λίαν γελοίως πεποίηκεν ἐκ τῶν ὤμων τοῦ Διομήδους καιόμενον πῦρ: ἐκινδύνευσε γὰρ ἂν καταφλεχθῆναι ὁ ἥρως”.” The strokes of the lash do not seem to have been very formidable.”
The Homer-whipper “Zoilus the Ephesian criticises this passage and finds fault with the poet because he has quite ridiculously made fire burn from the shoulders of Diomedes. The hero would be in danger of being completely burnt up.