Checkusers are only supposed to run checks when they have good reason to assume the user they want to check is violating policy. If they knew he was editing through an open proxy, the proxy should've been blocked, if they didn't they were in violation by checking.* *As far as I'm concerned, editing through such a proxy is just as allowable as editing through AOL as long as the editor is not using the anonimity to cause any problems.
Mgm