To add to Venice's comment (sounds like we are in a meeting!) I would also say that in the scripture referenced at Matt 18:15-17, the word 'you' was not used in the plural tense. In the koine Greek there were two separate words for 'you'. One singular and one plural. In the NWT, the plural form is rendered in all caps (YOU).In verse 17 (NWT) it says:
If he does not listen to them, speak to the congregation. If he does not listen even to the congregation, let him be to you just as a man of the nations and as a tax collector.
So we see that Jesus was referring to the offended one when he said 'you', not the entire congregation (otherwise he would have said YOU). It's easy to miss in english since we use the word 'you' in both the singular and plural forms.Therefore, strictly from Jesus' words, we don't see any reference to congregational shunning for offences (even assuming treating one as a tax collector would mean shunning). It was an individual choice and not an official punishment that the entire congregation enforced.rem'A scientific opinion is one which there is some reason to believe is true; an unscientific opinion is one which is held for some reason other than its probable truth.' - Bertrand Russell