As the newcomer was about to be hanged in the Long Branch, the rope is around his neck when Chester comes out with a shotgun to stop the hanging...in the next scene as he'said getting off the mule, the rope is no longer around his neck.
It is very obvious that Aaron Spelling cannot play guitar; throughout most of the song he's strumming, there is only a head shot of him and we cannot see his hand movements. In addition he lipsynchs the tune someone else sings.