I have a colleague who is coming up for tenure review shortly, and there is a problem with his teaching history. He was hired to teach classes specifically in area X, although his research is in a slightly different area (Y). I was on the committee that hired him, and the teaching was a major part of what we were looking for.
However, this person has not taught any classes in area X, at all. I know from persona knowledge that he requested not to teach X in his first semester, and I have heard from others that he continued to not want to teach in that area. (I have no reason to doubt the veracity of this hearsay, and his teaching assignment requests can be documented for the tenure and promotion committee.) This has not turned out to be a serious problem in terms of covering classes. Somebody else, also from area Y, started teaching some classes in area X, and we later hired a full time person working in Y.
Yet I am still concerned that the assistant professor coming up for tenure has flouted the requirements of the position for which he was hired (which were clearly set forth in his offer letter from the dean). His research is fine, although not outstanding, and his teaching in other areas would normally be considered adequate. He also does fine in other considerations (service, collegiality) as well. However, I am not sure whether it is appropriate to vote in favor of his tenure case, and I was wondering whether what others might think to be appropriate in such a situation.