They all laid hold on Sosthenes (epilabomenoi pantes Sōsthenēn). See note on Act 16:19; and note on Act 17:19 for the same form. Here is violent hostile reaction against their leader who had failed so miserably.
Beat him (etupton). Inchoative imperfect active, began to beat him, even if they could not beat Paul. Sosthenes succeeded Crispus (Act 18:8) when he went over to Paul. The beating did Sosthenes good for he too finally is a Christian (1Co 1:1), a co-worker with Paul whom he had sought to persecute.
And Gallio cared for none of these things (kai ouden toutōn tōi Galliōni emelen). Literally, “no one of these things was a care to Gallio.” The usually impersonal verb (melei, emelen, imperfect active) here has the nominative as in Luk 10:40. These words have been often misunderstood as a description of Gallio’s lack of interest in Christianity, a religious indifferentist. But that is quite beside the mark. Gallio looked the other way with a blind eye while Sosthenes got the beating which he richly deserved. That was a small detail for the police court, not for the proconsul’s concern. Gallio shows up well in Luke’s narrative as a clear headed judge who would not be led astray by Jewish subterfuges and with the courage to dismiss a mob.