Did I take advantage (επλεονεκτησα). Paul goes right to the point without hedging. For this verb from πλεον and εχω, to have more, see on 2. Corinthians 2:11; 2. Corinthians 7:2.

By any one of them (τινα--δι' αυτου). An anacoluthon for τινα is left in the accusative without a verb and δι' αυτου takes up the idea, "as to any one by him."

Whom (ων). The genitive relative is attracted from the accusative ους into the case of the unexpressed antecedent τουτον). Μη expects the negative answer as does μητ in 2. Corinthians 12:18.