He is in fact a waller, he was playing in the DG d2 server and it was just so blatant, not to mention the guy is a total douche, he's also in your clan, i consider you ban him right away, view his demo here, i dont' know how he cgot in considering he's a total douchebag,
if you'd like to view the demo and enable walls in it, type "sv_cheat 1" then "r_drawothermodels 2" in that order, in console, good luck, i've confirmed he is in fact hacking with other admins on my server
http://www.2shared.com/file/NGL5j4Ec/grey.html