mmm depends on how the server is setup, if its not set to view in 3rd per at all even in spec he is probably running a 3rd per hack.
For the 2nd shot with the red m4, I assume your running a pure server, but that skin doesnt look like an actual wallhack skin. Just a modified colour. Personally I don't ban unless a skin is giving a player an advantage i.e. Bright player skins or wallhack skins etc.
Even though a server is set to pure it is possible to get around that and use your own skins, remember not everyone intentionally tries to get around that. I was playing one day in our server which is a pure server when I switched to mp5 for a muck around to see my old gold mp5 skin appear.
