Uneven application. Corinthians example was less than a year.
You illustrate my point all the more. As I said, the scriptures do not support the concept of "total shunning" as applied by the Org today. In that case, because the man was repentant, Paul said he should be accepted back and not shamed any more.
A couple of other points:
1) The current "total shunning" policy creates potential absurd situations like this: an active JW is 'allowed' to talk to a work colleague who is a self-confessed satanist or staunch atheist/anti-religionist with an 'unscriptural' lifestyle, yet they are not 'allowed' to talk to a next-door neighbour who is a baptised JW who still believes in Jehovah, Jesus, the Bible, etc, but was disfellowshipped for a relatively minor sin or for a procedural reason.
2) In Paul's letters he wrote a number of times to warn brothers about the association they were having with some less reputable members of the congregation. In the letters to the congregations at the start of Revelation Jesus also warns some about tolerating the influence of "Jezebel". These were not people outside the congregation, but supposed 'brothers'. These warnings suggest that the early Christians did not apply total shunning but were free to an extent to apply discretion and their conscience in who they interacted with, otherwise why would they have to be cautioned so often about going too far in association?
Compare with today's JWs where it's rare for warnings about associating with the disfellowshipped to have to be mentioned because the total shunning policy is so rigorously enforced. (It does happen of course, but not often across an org of 8m people worldwide.)
Bottom line: the problem is not the concept of disfellowshipping, it's the policy of "total shunning". Total shunning does not have real support from the scriptures and it's also that that causes so much distress and harm.