I think that punishments shouldn't be as strict, and there should be a points system. Say, every player gets 10 points a month. Whenever they lose their connection during a PvP engagement, they lose one point regardless of whether it was deliberate or not. Once you run out of points, you get banned to solo for a week. This system would be more or less fair - everyone can clog from time to time and this covers people with unstable internet connections as well.How do you certify a clog as one?
I can't imagine an active PvPer losing their connection during combat more than ten times in a single month - if there is such a person, I would recommend switching your internet provider.