From the article linked in the OP:
"Knight is a lecturer in philosophy and religion. This is his second public intoxication offense. He pleaded guilty to a first offense one year ago."
A charge for public intox on his own time outside the classroom might raise some red flags, but probably would not lead to immediate dismissal. IN the classroom, during a lecture, is an altogether different story.
Having a "Dr" in front of your name is no guarantee that you are tenured faculty. About the only way to determine if they are tenured is to know their complete title - if they are an Associate Professor or (full) Professor or University Professor or Professor Emeritus they are generally tenured. If they are an Assistant Professor they may or may not be in a tenure track position. If they are Adjunct Assistant Professor or lecturer they probably are NOT tenure track.
@CycloneErik can probably correct any errors I've made here.