BTW, double jeopardy is already in existence in a practical sense see WP:SALT and you dont see many people complaining that its existense goes against the "consensus" model, why is it different for keeping articles?
Double jeopardy is the idea what once you've been found innocent you can't be tried again. The existence of WP:SALT is analogous to not giving convicted criminals an unlimited number of appeals. It is possible to appeal a salting, anyway - just go to requests for unprotection.