Note 15 — VI
Reading edition
This meaning of ἐπιβαρεῖν, taken as intransitive, is rather vague, but I believe substantially correct. If the word is to be taken as virtually transitive, the object must be the partisans of the offender. It would "bear hardly" on them, to assume that they had been grieved by what Paul considered an offence. They had not been grieved. That is why he excludes them from πάντας ὑμᾶς by ἀπὸ μέρους.